Diesel is a fuel that has had a mixed history, with varying levels of take-up by consumers around the world. In the world of transport, diesel engines have offered better fuel economy and torque than comparable gasoline engines. Particularly popular in Europe, diesel established a strong consumer base in both small commuter cars as well as heavy vehicles such as trucks and buses.
Despite this, the tide is turning, and for the average motorist, diesel’s days may be numbered. Why is this the case, and what are the potential alternatives vying for diesel’s crown?
Plenty of Pros, but Plenty of Cons
Diesel is a hydrocarbon fuel with several advantages over gasoline. Its lack of volatility makes it workable to use in a compression-ignition mode, and diesel engines can be run with lean fuel-air ratios. It also has a higher volumetric energy density than gasoline, and thanks to low volatility, diesel engines can run at significantly higher compression ratios without risking detonation. These benefits allow diesel engines to produce significantly more torque than similarly sized gasoline engines, and they can offer fuel economy gains in excess of 15%.
Unfortunately, diesel also comes with its fair share of drawbacks. Diesel engines are typically poor when it comes to power to weight ratio, as their high compression ratio and torque output demands heavier materials in their construction. The major bugbear of the diesel engine, however, is its emissions. Despite greater fuel efficiency, carbon dioxide output from a diesel engine is often far worse than that of a comparable gas motor. Additionally, their lean-burning nature leads to production of high levels of oxides of nitrogen (NOx), which have major negative environmental effects. There’s also the problem of particulate pollution, which is responsible for respiratory harm in humans. Diesel automobiles rank significantly worse than gasoline vehicles in all these areas. It’s begun to cause figurative headaches for the industry, and literal headaches for the public.
Major Mistakes Create A Foreboding Future
Diesel was doing just fine, enjoying a renaissance in the early 2000s as automakers touted the fuel economy benefits of their latest technology. In principle, the NOx problem is solvable by using selective catalytic reduction, but this comes at an increased cost to manufacturers and performance hit when the driver floors it.
Cracks suddenly appeared when researchers uncovered the fact that many vehicles from the Volkswagen Auto Group were blatantly breaking emissions regulations. Among other tricks, the cars were found to be running different fuel/air mixtures and underdosing the NOx-scrubbing catalyst outside of testing conditions, providing more power at the expense of dramatically increased emissions. Suddenly, hundreds of thousands of diesel cars were subject to recalls and buybacks. Recalled vehicles were subject to modifications to engine management software, which improved emissions at the cost of economy and performance. Almost overnight, the buying public learned that diesel wasn’t the eco-friendly panacea it had been made out to be. Diesels were suddenly seen to be dirty, polluting vehicles at the center of a major international scandal.
With the auto industry still dealing with the fallout years later, the image of diesel remains tainted. Cities are lining up to ban diesel cars from the streets, while Germany is putting cash incentives on the table to encourage owners of high polluting vehicles to trade up.
Solutions That Cause More Problems
Attempts to make diesel engines cleaner have had side-effects. In efforts to meet ever tightening emissions standards, automakers have implemented new technologies, akin to the introduction of catalytic converters in petrol engines. Many vehicles are now fitted with a diesel particulate filter (DPF) in order to help reduce particulate outflows. These are fitted to the exhaust, and capture the particulate matter from the combustion process. Over time, these filters begin to become clogged with soot, increasing back pressure in the exhaust system and reducing engine performance. When this happens, the filter must be regenerated, a process in which the exhaust temperature is raised higher in order to burn off the soot. This can be achieved passively during high-speed highway driving as exhaust heat builds up, but many cars that are driven in stop-start urban environments must resort to other methods. This is referred to as active regeneration, where extra diesel is injected into the exhaust, or the engine is run at high RPM while stationary for a period of time.
DPF filters have proven problematic in practice. For many living in inner-city areas, diesels with DPFs fitted may be impractical, as the engine is forced to run active regeneration cycles regularly to make up for the lack of highway miles. Due to poor communications practices by dealerships, many owners are completely unaware of this quirk of modern diesel cars, leading to regular frustration with clogged DPFs. Further complicating the issue, some manufacturers have struggled to correctly develop regeneration routines in some vehicles, leading to consumer frustration and class action lawsuits.
The Aftermarket Isn’t Helping
Despite its flaws, diesel still has its diehard fans. The darling of those who regularly tow heavy loads or drive long highway miles, these drivers prize the torque delivery of a strong diesel engine. Tuning diesel engines has become a major aftermarket industry, with companies touting improved power delivery as well as better fuel economy from their products.
Of course, nothing comes for free, and gaining better performance often involves a trade-off somewhere else. More often than not, tuning a stock diesel engine results in a vehicle that is no longer emissions compliant. This has raised the ire of the EPA, which has brought down hefty penalties upon companies selling tuning gear. This is primarily due to tuners often using software and hardware tools to bypass emissions controls like oxygen sensors and particulate filters in the quest for more power.
At the extreme end of diesel tuning is the practice known as “rolling coal”. This involves tricking a vehicle’s ECU into dumping excessive amounts of fuel into the engine, in order to create large amounts of soot to pour from the exhuasts. This is done for fun, or to harass other road users. While it’s a pastime of a fairly small minority, it’s not winning diesel any fans, and has already been made illegal in state law in Maryland and Colorado. The EPA have long claimed the practice is a clear contravention of the Clean Air Act.
A Poor Outlook
Moving forward, the future doesn’t look rosy for diesel. The push to reduce carbon emissions promises to impact all fossil fuels. However, diesel, with its high output of NOx, particulates, and CO2, looks set to be consigned to the dustbin sooner than most. Efforts to clean up diesel engines have led to complicated emissions systems with dubious reliability and manufacturers attempting to skirt regulations. With electric vehicles rapidly gaining market share, and alternatives like hydrogen vying for relevance, conditions are tough. Worse, European and Asian countries are all planning to phase out fossil fuel vehicles entirely. In this fraught environment, it seems unlikely automakers will be willing to make the necessary investments to push diesel technology much further, leaving it to slowly wither away as regulations tighter. As always, time will tell.
“Despite greater fuel efficiency, carbon dioxide output from a diesel engine is often far worse than that of a comparable gas motor”
how is that possible?
How is it not possible?
Because the fuel efficiency is significantly higher, so less fuel is used, and the fuel does not have that much more carbon in it, so it is impossible to conjure up extra CO2 out of nowhere.
Because it’s bs. It’s well known that diesel produces less CO2 but more nox. CO2 basically isn’t addressed at all in diesel emissions because it’s so low
+1 this post as you made use of common sense.
Carbon dioxide output from an average diesel engine is lower not higher compared to an average gasoline engine for the same mechanical power. In theory it could be the other way around, but as pointed in the article the efficiency is typically higher of a diesel engine which has a greater impact compared to the higher carbon to hydrogen ratio of the diesel fuel.
My diesel is a European class 6 engine cleaner than any in bed I wish I could add a photo go prove that
Guys chill. The article doesn’t mention the Euro6 diesel, order of magnitude cleaner (and less powerful :D) than euro 5 and below. The legal limits of euro 6 are similar to gasoline engine in all dimensions (source: Wikipedia et all)
I work as a diesel engine development engineer for one of the “big four”.
The €6.2 engine that I am working on makes exactly the same power as the €4 version of the same engine.
And at 200+ hp from a 2.0 litre engine, it isn’t a tiny amount of power either.
Cool. I was joking based on the claims after the diesel gate of a reduced power felt by the users. My €6 car has 80hp, i can’t really tell. For sure i know is polluting less than a 200hp gasoline, but i will end up paying more in taxes than a guy owning a huge gasoline rams, because mine is a diesel. I hate that, because is unfair. Please moderate the comments with your knowledge :D
Diesel engines don’t emit more co2 than a gas engine. It releases more NOX and PMs at idle than a gas engine.
Diesel has longer hydrocarbon chains, which means more C for each H, which means there is less liters of fuel used, but more CO2 emitted (with much less H2O). Beside emitting several percent more CO2 (yeah, it’s not THAT bad), they emit several times more NOx and particulates, which is worse for you personally than CO2.
the amount of C per kg in diesel vs. gasoline is within 1%.
That is because diesel is denser than petrol, 1 kg of diesel is 1.202L, 1kg of petrol is 1.342L.
and a diesel is more efficient so it uses less. With less C going in there can’t possibly be more CO2 going out
“and a diesel is more efficient so it uses less.”
It uses less *volume*, it doesn’t use less *mass*. Diesel has a higher volumetric energy density. It has a lower specific energy. Fuel economy is volumetric: km/L, not km/kg.
Gasoline: 46.4 MJ/kg, 34.2 MJ/L
Diesel: 45.6 MJ/kg, 38.6 MJ/L
a diesel engine is more than a few percent higher efficiency than a gasoline engine so the diesel uses less mass as well
“a diesel engine is more than a few percent higher efficiency than a gasoline engine so the diesel uses less mass as well”
You keep saying “diesel engine” and “gasoline engine” as if there’s like, one master version of each. Like, you can pull out a car with crappy fuel efficiency – say, 30 mpg – and compare it with a high-efficiency diesel – say, 40 mpg – and say “hey look, the diesel gets 33% higher gas mileage!” There are plenty of 40 mpg gasoline cars, too.
The place where diesel wins is that it’s more fuel efficient for higher-output engines – hence trucks, heavy equipment, etc. But at peak fuel efficiency (distance per volume) they’re not really better than what you’d expect from the volumetric energy difference.
And you can make up for the fact that you get the best overall efficiency when you tune a gasoline engine for high-RPM usage, meaning it has no power at low speeds: you add an engine that has high torque at low-RPM. In other words, a hybrid.
A hybrid gas engine is *still a gasoline engine*. Saying “oh, you can’t count hybrid vehicles, just pure ICE” is like saying “oh, you can’t use diesel sedans, you can only use trucks”. Can you make a hybrid diesel engine? Of course, Mercedes did. But hybrid designs improve gas engines far more than they improve diesel engines. You don’t have 70 mpg highway rated diesel hybrid engines.
I’m actually not trying to say that diesels put out more CO2 than gas engines – I disagree with the article there. It’s pretty much a wash between the two.
But it’s nuts to claim that diesel puts out significantly *less* CO2 than a gasoline. In terms of “energy per emitted kg of CO2” the two fuels are essentially the same. It doesn’t matter.
Why should CO2 be a problem? CO2 is food for plants, and for this role we rather have not enough CO2 in the air. The propagated “CO2 is a greenhouse gas” dogma is IMHO actually falling apart. One should always ask: cui bono?
I don’t have a link right now, but you can look this up for yourself if you dare. Yes, plants take in CO2 & produce O2 as a byproduct, but 1) humans are putting so much CO2 in the air & wiping out so many plants that plants don’t mean a thing to the average CO2 level & 2) agricultural plants used to produce food when exposed to high concentrations of CO2 grow more plant than food.
So, yes excessive CO2 is a problem.
Good grief the same tired straw man argument being perpetrated. While Ice cores can tell us the history of green house gases on our planet, there is an important factor they can’t tell us, the existence of any other periods where conditions that are in effect today, existed. That is humans simultaneously, releasing prehistoric carbon, while reducing the amount of plant life.
Too much CO2 in the amtosphere can be a problem but diesels have a trick up their sleeves their fuel can be directly made from plants which solves most of the emissions problems and makes them carbon neutral and have a much cleaner life cycle than most EVs.
LiFePO4 based battery EVs might be cleaner when their entire life cycle is considered but ones using NCA and NCM chem cells will never get with in spitting distance of a small efficient diesel.
That said deforestation is a much bigger problem as far as atmospheric CO2 goes than emissions from road vehicles and aircraft and it also a lot dirtier as far as NOx and particulates goes.
Not many have mentioned this. Light liquid fuels CAN be made from plants—ethanol, methanol, and most usefully, butanol. But it’s not nearly as cheap or easy as making biodiesel, at least not yet. There’s no way processing (or not, in some cases) used cooking oil for diesels can supply more than a small percentage of the population with motor fuel, but for those few it’s pretty cool, especially when your car smells like french fries rather than flounder.
Unfortunately, there are various types of nanoparticles emitted from all ICEs that could prove to be harmful to humans in particular, as they can apparently migrate from sinuses to the brain without going through the lung/blood route. There are no catalysts or filters that can fix that. ICEs in general are likely doomed in future mass-production passenger vehicles.
Nobody much seems to be seriously working on it now, but pure electric vehicles needn’t be powered by batteries, either. There are at least two other ways: massive arrays of tiny flywheel-like storage devices, and capacitors. Most assume they can’t compete economically with batteries, but it’s partly because no one’s moved along the learning curve and scaled up production to where they might.
cause diesels produce less carbon monoxide, if we look at CO Vs CO2 as a ratio. I know running a petrol vehicle in my workshop for a few minutes will set off my CO alarm but i wont notice any difference in air quality, but can run an (older) diesel until my eyes are stinging from the fumes yet the CO alarm stays silent.
Im pro-diesel. most my vehicles are diesel, of them, i have 2 530 bmws, one petrol one diesel, the diesel is faster, better around town and averages, with my driving style, twice the fuel economy of the petrol. for every litre of diesel I would have to burn 2 litres of petrol, I appreciate the current fascination with particulate emissions, but surely burning half the fuel counts for something.
Am in the UK, and realise that most folk reading this site are in the USA and uptake of smaller diesel vehicles has been really poor there. IMHO due to your low fuel prices but am sure there are other factors.
the three-way cat on a gasoline car takes care of HC, CO and NOx. A diesel always run lean so there is little HC and CO but a catalytic converter cannot reduce the NOx because of the excess oxygen
Three way cats do help reduce HC, CO and NOx, yes, but when you first cold start a vehicle, before the cat lights off there is a substantial amount of CO and HC. And, even when the cat has lit off, diesels still emit less CO and HC than the comparable gas engine.
You are correct, though, three way catalysts like what gas engines use cannot be used on diesels to reduce NOx. They have to oscillate on either side of 14.7:1 air/fuel ratio to work correctly and diesels simply cannot run that rich, otherwise they just belch a ton of smoke and you lose the entire reason for having the engine design: efficiency.
So, other methods have to be employed to reduce it, namely EGR and the most effective solution that everyone now is using: SCR with DEF. When those systems are designed and working correctly (i.e. not cheating the system) they are indeed extraordinarily effective at reducing NOx to very low levels (less than a tenth of a gram per mile effective).
Guys. Pleeeease, when you do all these tests, do it on a Diesel and or Petrol engine that is in100% condition. When an engine pillows out smoke then it is heavily faulty. The latest Diesels are very fine tuned with minute amounts of bad immitions.
EGR doesnt help with NOx. It actually makes the engine run hotter.
DEF is also hit and miss. If you inject too much, you end up producing ammonia, and it’s not trivial to dose correctly without knowing exactly how much NOx there is in the exhaust – which depends on a lot of things. That’s why the manufacturers err on the side of safety and inject too little, or not at all, for example when the temperature is too low.
DEF only really works when the engine is running at a steady state, or close to it, such as in the emissions test stand where the load profile is known in advance.
https://www.xkcd.com/386/
EGR does reduce NOx by reducing the amount of available oxygen in the cylinder.
It does not necessarily increase combustion temperature if it passes via an EGR cooler.
DEF injection rate is (or at least can be) based on the measurements made by NOx sensors in the exhaust. It isn’t done open-loop.
It runs lean + much higher compression (like up to 25/1). = more NOx. Environment in the cylinder at combustion is way different. Petrol is around 1000 deg C and 50 atmospheres. Diesel is around 2500 deg C and 100 atmospheres. (Recalling from a friend who researches this stuff.)
What diesel engine runs over 20/1, most are alot lower than ever now, better fuel so no need for those high compression rates
Cole Harmon: It gets confusing. Normally aspirated diesels can have up to 25 to one. Modern engines are all turbo/supercharged, giving an ignition pressure the same as a 20 to 24 compression ratio without the long strokes. Then I think peak pressures are much higher than petrol due to the combustion temperatures.
In many parts of the USA, diesel fuel is significantly more expensive than gasoline (petrol).
But, the main thing that killed the diesel car here was the horrible diesel engines General Motors made in the late 1970s and early 1980s. They were based on gasoline engines and not able to handle the higher stresses of the diesel. They were so bad that they often failed before 10,000 miles!
Even though VW and Mercedes sold decent diesel cars at the time, the General Motors ones ruined the public perception of diesels.
I definitely agree with you. Unfortunately Ford has put out two diesel engines in the last 10 years that has also reinforced this idea: the 6.0 liter and the 6.4 liter. Both engines injected diesel during the exhaust stroke to pass the diesel to the SCR for buring. This caused huge issues with the diesel passing by the rings of the piston and ending up in the oil pan. Many sub 100,000 mile engines were ruined. Because of this, many people ended up bypassing the emissions systems with tuners. They were concerned their 50,000-80,000 dollar truck was going to need a new engine in only a few years driving.
Not the right solution, but I can understand. Poor engineering created an issue that has never really been resolved.
The 6.0 did not have an SCR.
The 6.0L are just brutal. So many issues. They replaced the very reliable 7.3L which would do a million miles and long outlive the body of the truck. We have a fleet of plow trucks and still have two 7.3’s on the road. We have six 6.0L and they are all broke down. We have one 6.4L and it’s on it’s second motor. We have switched to using small freight liners, internationals and sterlings because in the long run they are cheaper to keep on the road.
Diesel used to be significantly cheaper in the 90/early 2000s in the US before low sulphur became the norm. Probably why it was so popular with 18wheeler trucks. Better mpg and cheaper per gallon than gas/petrol.
GM cut corners and left out a fuel water separator combine that with the low quality fuel in the 1980s you have a problem.
Ironically once they added a separator and used improved head bolts and gaskets the engine were very reliable but the damage to their reputation was done and the public wanted nothing to do with the Oldsmobile line of diesels.
Kinda the same thing that happened to Apple Computer with the Apple III as the III+ was actually was a decent computer.
Well, it’s all mostly about Europe now. However, the Noth America must quickly catch on! If there are now better alternatives, to cleaner engines or electric powered trucks, get rid of the diesel.. Just sayin’..
In Europe a 2.0L engine diesel is considered a beast. We usually have a 1.4L engines in average, and with equal horsepower, the diesel emit less CO2 than gasoline (15% ish). I just say this from the legal declaration from Audi and Volkswagen – so I hope now they make sense after the diesel gate came out. Just check on the Seat brand. So i don’t get the article, seems quite an US vision hyped with a bad technological usage of such diesel. I don’t know if this ratio become worse when using 6L truck engines to go to the supermarket – in the US. (I make easy irony… not provoking :D)
I have the same thoughts marginally more emissions per gallon, but far less emissions per mile, I’m UK too.
Also emissions on a petrol engine with 100k miles on it are significantly higher than when new, as opposed to similar diesel having closer to as new emission levels.
We have 5 vehicles, all diesel, all are massively under permitted emission levels at annual testing most have 150 – 200k miles on them.
Going to petrol would also more than double the fuel cost, especially as we regularly tow a 3.5 ton trailer and drive off road hence Discovery and Defenders.
Electric vehicle comes nowhere as a comparison due to purchase cost and non have towing ability.
One of the reasons for the relatively poor uptake of diesels in the US (even prior to Dieselgate, which looks to be killing them off here) is that the tax situation makes diesel fuel considerably more expensive than gasoline here – enough that it is just as expensive to run one as a regular gas car.
Another thing to keep in mind: it’s not like refiners can just choose to make a barrel of oil into gas or diesel. As far as I remember, the average barrel works out to roughly 2/3 gasoline and 1/3 diesel (with other small percentages of stuff like kerosene. Refiners can move those percentages a bit, but not much. I had heard (don’t have any sources close at hand) that a significant portion of the diesel fuel that Europe uses is imported from the U.S. where it is extraneous. If Europe moves over to Gasoline, Not sure what that will do to Gas prices over here – and what we will do with all that leftover diesel…
Fuel economy is measured in litres per kilometer, because you pay by the litre. Diesel is denser (more mass per liter) because it is made of heavier fractions, and contains more carbon per litre. So when you burn it, you get more carbon out because more goes into the engine. Pretty straight forward.
yes diesel is denser but diesel also have better mileage because it is more efficient
Doesn’t equal out. Gasoline has a higher specific energy than diesel, but lower volumetric energy density.
diesel is only ~10% more energy per liter, diesels are commonly ~25% better mileage so the diesel still comes out ahead
Diesel compression is more than twice as high, and more than twice as hot. As an example of the carbon content, petrol octane has carbon/hydrogen of 4/9. Typical diesel is made of parafins and aromatic hydrocarbons and it averages out to a ratio of 1/2 (same as methane). So diesel has 1/9 more carbon. On the other hand, diesel is about 12% denser than petrol, and you get about 12% more energy per liter. I would guess diesel makes a little more CO2 than petrol.
Modern gas engines for cars have anywhere from an 11 to 1 to a 14 to 1 compression ratio…a modern diesel like from bmw has around a 16 to 1 compression ratio..the new Mazda skyactiv diesel has around 15.5 to 1…so a modern diesel has closer to 20% more compression than a modern gas engine.
Are you considering only the mechanical compression ratio? bear in mind that most diesels are now turbocharged, and mechanical compression ratios have been decreasing while boost pressure ratios have been increasing. (This is true for both types of boosted engines)
3.5 bar manifold pressure (absolute) is not unusual on a modern turbo diesel, so the true compression ratio might be 3.5 x higher than the mechanical ratio. (but probably isn’t, because cylinder filling is unlikely to be 100% at the speeds and loads where the boost setpoint is so high)
Gasoline engines are 8 to 14. Diesels are 16 to 25. Petrol combustion 1000 deg C. Diesel 2500 deg C. IIRC
Forget all this mumbo jumbo. Just try to kill yourself with diesel fumes first, then try petrol fumes. You wont wake up the second time. Guatanteed. This is the bottom line. There is non other. I rest my case.
I presume you’ve done the experiment?
Elliot I’ve been doing it all my life.
Methane doesn’t have 1:2 C:H, it’s 1:4.
“I would guess diesel makes a little more CO2 than petrol.”
Possibly per litre burned, possibly per kg burned, possibly per kJ of energy output, but not per mile driven because diesel cars are (in my experience) about 30% more efficient (in distance/fuel volume) than petrol ones. That last one is the most important statistic if you ask me.
It’s definitely the one of the things that gives me pause about the article’s accuracy. From the EPA’s own findings:
A gallon of gasoline when burned will emit 8887 grams of CO2
A gallon of diesel when burned will emit 10,180 grams of CO2. So yes, diesel is more carbon intensive, however, the increase in fuel economy of a comparable diesel engine is usually more than enough to make a diesel emit less CO2.
So, for example, if you have a gas engine that gets 30 MPG (which is pretty typical for a 4 cylinder gas engine in an average sedan), you take 8887 grams CO2 divide it by the 30 miles per gallon and you get your grams per MILE of CO2. That comes out to 296.233.. grams per mile CO2.
Realistically, many of the VW diesels are going to average somewhere close to 42 MPG. Take 10,180 grams CO2 / 42 MPG and you get 242.38 grams/mile CO2. The lower output of CO2 thanks to the efficiency of the diesel engine is the primary reason Europe incentivized the mass adoption of diesels long before there existed technology to make them genuinely clean. In light duty cars, gas engines have closed the gap in terms of efficiency, but in heavier, less aerodynamic vehicles, diesel still has a substantial advantage in efficiency.
For example:
2020 Chevrolet Silverado 4×2 5.3L gas engine, XFE package (slightly better fuel economy) is EPA rated at 19 MPG combined city/highway, which comes out to 467.7 g/mi CO2.
Same 2020 Silverado 4×2, except now equipped with the 3.0L Duramax diesel is rated at 27 MPG combined (and 33 highway!! Unreal) which comes out to 377 g/mi CO2…
And, just for scale, ALL of the regulated gases that actually cause pollution (CO2 isn’t a pollutant, it’s a climate concern) combine for less than 1 g/mi. Those gases include Carbon Monoxide (CO), Hydrocarbons (HC), Nitrogen Oxides (NOx, which could be in the form of NO, NO2, NO3…) and Non-methane Organic Gases (NMOGs).
I could go on about a couple other questionable facts in this report, but overall it’s not as inaccurately informed as some I’ve read on this topic.
They are correct though when they say diesels are problematic in the city environment. They definitely have more issues at lower miles than diesels that do primarily highway driving. As I like to say, different tools for different jobs. Diesels are still a viable and fantastically efficient and good to drive concept on long highway trips and for hauling loads.
“From the EPA’s own findings:
A gallon of gasoline when burned will emit 8887 grams of CO2”
Mixing metric with gallons…
So, the U.S. Government hasn’t learned from the Mars Climate Orbiter in 1999.
goteem
The orbiter would have crashed just as hard if it got “grams·meter/minute” instead of the expected newton seconds (kg·m/s).
The failure was not metric vs US units it was not following the Software Interface Specification.
Most Americans don’t understand the metric system so they converted the liquid mass in to gallons and grams is a scientific measurement. And it’s probably a good thing but they’re not going into ppm’s! Because that would probably throw just about every average reader for a loop!
You are right. I deal in ppm’s and ppb’s and up to ppt’s in the Semiconductor gases usages. Glad there are people out there that understand gas emissions and toxicity.
I own a diesel motorhome and love the efficiency on long trips. Would never use it in City short trip driving. LOL!
BC
This is better than the article.
+1
+1 unlike the author of the article he seemed to have actually did his homework and had actual figures to back up the claims.
Thank Dieseldub. The comparisons looks very impressive on paper, we must remember that a Diesel engine runs at very very low rpms compared to petrol engines doing the same distances, thus putting the coyote amongst the chickens with the calculations. So our learned friends will have to go back to the drawing board to try and convince me. Petrol fumes WILL KILL YOU. Diesel will not. I am a Diesel Mech, and at SEVENTY one, I am still working everyday. Living proof.
Both will kill you, it’s just that petrol would do it faster
The author of this has never seen a truck stop or construction site. There are no gasoline front end loaders, there are no gasoline rigs. Diesel will be a very safe bet for at least another 100 years.
yap
Yeah, assuming nothing in the environment or supply chain changes. Which is certainly not a bet I would take.
There are electric rigs in the works. I would expect that well within a century. I sure hope so at least.
The next decade or so? Probably…the next hundred years? Unlikely….electric vehicles like Tesla have already proven to be more powerful and have way more torque even at this early stage..And they only get more powerful and efficient every year..in fact they recently introduced an electric semi that is faster and can pull more than any diesel ever could.
Htm. That is the prototype I presume? Let them mass produce them, then we will see how practical it will be. Diesel forever!!!!!
Even without climate change, there won’t be diesel forever. Oil is a finite resource, we would be out of easily recoverable oil by now if it wasn’t for the fracking, which bought us a few more decades. It will eventually run out. Maybe even sooner rather than later. The US is pumping it out of the ground very quickly.
Well I guess there could be biodiesel but I don’t think that can scale up to today’s oil consumption and still leave enough farm land for food.
The Tesla semi is a paper tiger. The batteries take so much out of the cargo mass that it’s not viable in practice
@LordGarak
Crude oil is a limited resource but bio diesel is a renewable resource and can be made from many things such as soy,hemp,tallow,corn, and even algae.
I think it might even be more sustainable than most types of lithium ion battery as easily mined cobalt and rare earths can run out.
Hear Hear Doc mangler.
New idea have the epa replace our diesels for. A gas pig or electric power system.our diesels are our choice. Create your replace for our needs or shut up.
Perhaps it’s because of my age, combined with teachers that demanded we stick with fact, it’s, how I operate.By design, EPA regulations like most regulations in the USA are written by the industries being regulated. In the event your choices and need , mean figuratively peeing/pooping in our collective water well, you are on the wrong side of the coin.
It is false. Diesel burns cleaner than gas but you can see it…so people think it’s worse. That’s it. Its a fact.
Good Dave. Just to add to this. This is just another SCAM like the different fuel grades. They still cannot prove their claims of ” more power, better economy and all other mumbo jumbo. Just to remind the people that ALL these new petrol and diesel engines have preset timing. No fuel in the World can burn faster and make you car go faster or more economical. The lower sulphur content diesel fuels are damaging the engines. When using these, add normal two-stroke oil to the diesel to save your components like injectors an pumps. It is ALL about making money. There are NO BENEFITS in it. Stick to your high 500 ppm Diesel or else suffer the brunt. And just for the record. Use only SAE 30 OR SAE 40 engine oil in ALL Petrol and Diesel engines, Turbo charged on not, enjoy real lubrication. Forget ALL Multi-grades and synthetic oils. Diesel and Petrol Mech with fifty eight years of practical experience and still working. Its all about money.
If anything, it spews less CO2. But it does produce a lot more CO per volume of fuel used. At least my Cummins Isx does to my Honda 2.5 liter.
I also deleted my dpf, def,egr. Now it spews out quite a concoction.
Correct,you know why they want to junk diesel coz its the way of our life what ever they wanna lobby for money they push it
Fonz, if that is the case then your Diesel engine is in very bad shape and of the old generation. By the way. The catalytic converters/ particulate filters are SCAMS. It will like any other filter clog up if your engine is smoking. Check the prices of these items. Money making!!!!! It’s all about money. And we who believes in them are the Idiots.
Some actual numbers:
https://www.fleetnews.co.uk/cars/Car-CO2-and-fuel-economy-mpg-figures?CarType=&Manufacturer=ford&Model=focus&CO2To=&EquaMpgFrom=&SortBy=Manufacturer&SortDesc=False&FuelType=
(The 1.0 “Ecoboost” engines are petrol / gasoline, the 1.5 “EcoBlue” is a diesel.)
For the same rated power output the diesels are consistently a little _lower_ in CO2.
+1 if I was to ban any kind of engine it would be small displacement turbo charged engines as the vehicles with them generally have a shorter service life and a large part of a vehicle’s emissions is in it’s manufacturing.
I’d also ban use of glue in EV battery packs and phones while I was at it.
I don’t think it’s correct. There are news reports indicating that the VW buyback had an adverse impact on yearly CO2 emissions for the planet because so many owners turned to gasoline engines.
It’s not possible if you read up on current diesel engine specs, for instance, the DDEC15 Detroit puts out cleaner air than most poeple take in because of the DPF System. These are lies. Diesel engine market is rising with more and more cars coming stock with said engines. Also another thing that was true was the output to weight ratio. Engine makers have already cut the weight down significantly in the past decade than ever before. Yes the engines way more but exceed immensely higher levels of power, fuel economy, and emissions than gas engines. Because all of the nOx gases are burnt up by the DPF system.
There has been no thought for the people that has repaired these engine what exposure they have had I was exposed to them for 42 years.
I expect diesel to stick around in the markets it owns. Large pickup trucks, Semi trucks, and large marine engines.
Once we have reliable 300mp charge electric cars in the 20-30k range i don’t see myself bothering with all the work thats involved in burner engines anymore.
The person who wrote this click bait article doesn’t know anything on the subject.
Replace diesel fuel with biodiesel made from algae. Algae farms will cancel out CO2 emissions from engines. One can also use different oils as fuel for diesel engines, including waste oil from fryers…
The CO2 is the least of the problems in a cars exhaust. The amount of NOx in diesel exhaust gas is a whole lot higher and that stuff is just plain toxic.
Bio Diesel from Algae actually has the same drawback as Bio Diesel from rapeseed, you need space that get’s sunlight.
And if I remember correctly the efficiency of rapeseed growth is much higher than from algae.
And yes even if the energy is free efficiency matters, as the resource(land) is limited.
Currently pv solar to batteries has the highest efficiency from Sunlight to wheel.
black panel(less reflection)s vs. green plants/algae(more reflection)
Oil from plants requires some major resources: fertile ground and plenty of water. Algae on the other hand can be grown in closed-loop system with minimal need for additional water, therefore you can place the entire system in some place that has no useful land at all. Algae are processed in high-pressure cooker, which creates crude oil, water and some organic left-overs which can be reused as fertilizing agent for the algae.
We are nearing the limit of battery technology. The only valid solution to efficient storage of huge amounts of energy is some form of chemical fuel. Even when we use up all the fossil fuels we have, it will be cheaper to make more than to switch over to only electric vehicles…
I’m getting old enough now that I feel funny when someone says “nearing the limit”. Given what I’ve seen in my middle-aged life (pocket Crays with multi-megabit microwave links, ubiquitous in nearly every middle-class pocket, a decade ago) I suspect we’ll see batteries that get measurably heavier as they charge before my life is over. Reversible fusion or something… I don’t know. Crazier things have happened. Like custom antibodies that stick to cancer cells (cetuximab). Atomic force microscopes. 3D printers cheaper than tennis shoes…
Every technology has its practical limits. Just because one has is limits higher does not mean an entirely different technology is the same.
Well, we are nearing the limits of silicone-based computing. That’s why CPU clocks didn’t increase much in past 5-10 years compared to 10 or 20 years before. Instead we’re making more efficient use of current technology and moving to parallel processing, increasing memory access speed and data transfer speed from and to storage. This is reason why modern supercomputers are not clocking at 10-100 times the CPU clock of typical PC, instead they have thousands and thousands of CPUs working in parallel…
Battery technology for all the practical purposes is near the energy density limit. We can improve the charging time, number of cycles without loosing the capacity, maybe even some safety, but we won’t make a battery that stores the same amount of energy as fuel tank while having the same size as fuel tank. O once calculated that the best electric car (first or second Tesla car) had range 7 times worse than piece of junk (Fiat 125p) made in eastern block in 1970s. And I compared best case scenario for Tesla with average fuel consumption for the Fiat. Public transportation systems, like trains, trams or metro can run on electricity. Cars? Okay in cities and if you don’t really care for manufacturing costs and how they are recycled, and the way batteries will die from fast charging, but for longer trips I’d rather have a diesel or gasoline/LPG/CNG car. Plus, they are so expensive that in many places state has to give money to people so they can afford them. Otherwise they wouldn’t bother…
And the other thing: in most countries electrical energy is produced by burning fossil fuels, sometimes supplemented with bio-fuels, like pellets made from willow wood, just to meet some stupid CO2 limits in EU, while 3/4 of the world doesn’t give a flying duck…
>” maybe even some safety”
Increasing the energy density from today’s batteries will inevitably lead to worse safety, because the reactivity of the battery goes up the more energy it packs into a smaller volume and mass.
In a battery, you have two types of chemicals that want to react with each other and release the potential energy through a chemical reaction. They are separated by a thin membrane and some electrolyte which limits the rate of reaction, and protected by a shell that keeps any runaway reaction from spreading into adjacent cells. These materials make up the majority of the mass of the battery. Reducing the mass and volume of the battery, while increasing its charge rate and power capacity, necessarily involves reducing these safety barriers to the point where your battery starts behaving more and more like gunpowder and eventually, like high explosives.
Maybe reaching the limit in conventional battery technology!
New research into graphine battery technology is looking very promising.
Algae that grows in the ocean gets around the land use problem – there’s 3x as much ocean as there is land.
Nuclear and hydroelectric are the best sources to charge EVs since they have a better ROI than PV solar which isn’t that good on large scale unless you have a convenient desert with nearly 365 sunshine and then you still have the dreaded duck curve.
Chemical fuels though can be stored for long term ie energy gathered in the summer can be used in the winter while energy in rechargeable batteries is a use it or lose it proposal as it’ll be gone in a month or two.
Though my biggest gripe with the EV movement is they settled on NCA and NCM cells when LiFePO4 cells are safer,are much cleaner to manufacture and have a much longer lifespan.
This biodiesel racket is just as much of a crock as those carbon-exraction schemes that aim to pull carbon out of the atmosphere, turn it back into gasoline, and sell it.
It doesn’t magically make it the exclusive source of the fuel. It’s still gonna be cheap to pull it out of the ground, and people are still going to need a whole lot, so people won’t choose one source. They’ll use both.
So you’ll have on one hand an industry pumping every single last drop of hydrocarbon out of the earth and putting it into the atmosphere. And you’ll have these hokey fraudulent greenwashed companies that make carbon in the atmosphere into a form that can be burned again and put right back up there. A net-zero carbon tech still leaves our atmosphere full of carbon. Essentially they’re designing a way for the carbon to stay there forever.
if anything is a crock green washed BS right now it might be many EVs since the batteries are not recycled and some companies are not friendly to service and repair of the vehicles.
I saw one glue the cells together in the pack so you cannot even up-cycle the still good cells in an old pack without damaging them.
Another thing that is a real crock is the idea you can just throw stuff in a chipper and recycle it aka Apple’s answer to pollution.
This might be a better solution for long range vehicles than trying to make them battery electric as the battery pack gets too large.
Batteries are not emissions free in fact some parts of their manufacturing can be very polluting and energy intensive.
Lithium is not that bad pollution wise but still needs a vast amount of energy but cobalt is a mess to extract and refine and many of the mines are located in environmentally sensitive regions such as the Congo.
https://www.washingtonpost.com/graphics/business/batteries/congo-cobalt-mining-for-lithium-ion-battery/
A strange irony the old lead acid tech probably is cleaner than cobalt cathode lithium batteries since they are regularly recycled.
This is why a Tesla 3 is unlikely to ever achieve emissions parody with a Toyota Corolla or a Prius.
The Prius needs less of the a fore mentioned materials,
Diesel produces LESS co2 per kilometer/mile than gasoline.
It does, however produce more NOx
The switch back from diesel to gasoline is part of the reason why co2 production rises in Europe
Can we find some way to capture that NO₂ and put it in whippits and then mail all those to me?
N₂O, my bad
at least there is an ongoing effort to improve/cleanup diesel emissions..
gasoline emissions are for the most parts not even acknowledged..
diesel emissions are comparable to a barbecue or a bonfire. (bad for your lungs)
while gasoline emissions are more like paint fumes. (bad for your brain/mental health)
does anyone know if there is NOx emissions from 100% bio-diesel/vegetable oil?
the CO2 should be of no concern if its not from fossil fuels..
and what about ethanol/alcohol?
> while gasoline emissions are more like paint fumes
Hmm, never heard that before, could you elaborate? I’m just curious and would like to know more about this.
it is nonsense
gasoline contains mostly (55–77%) saturated hydrocarbons, 9–50% aromatics including benzene, some unsaturated hydrocarbons, less than 10% ethanol.
benzene can be found in most all glossy paints, as well as spray paints and paint thinners.
most common aromatic compounds are derivatives of benzene.
at least 9–50% like paint fumes..
which it is irrelevant since it gets burned, not poured out the exhaust pipe
Cold engines with cold catalytic converters emit unburned hydrocarbons, which produces the paint thinner emissions effect. This happens every time you start up the car.
And the ethanol/methanol added to fuels produces formaldehyde and acetaldehyde, which are carsinogenic and a major contributor to lung cancer.
it contains a number mixture of volatile, flammable liquid hydrocarbons and volatile organic compounds (VOCs).
the composition of VOCs varies from brand to brand, in neat gasoline, 29 target VOCs were detected.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4324831/
gasoline contains mostly (55–77%) saturated hydrocarbons, 9–36% aromatics including benzene, some unsaturated hydrocarbons, less than 10% ethanol.
the content of aromatics+ethanol -> 18-45% paint fumes
just to mention one of the known VOCs:
“benzene is ubiquitous in gasoline and hydrocarbon fuels are in use everywhere, human exposure to benzene is a global health problem. Benzene targets liver, kidney, lung, heart and the brain and can cause DNA strand breaks, chromosomal damage, etc. Benzene causes cancer in animals including humans. Benzene has been shown to cause cancer in both sexes of multiple species of laboratory animals exposed via various routes.”
https://en.wikipedia.org/wiki/Benzene
and then there is leaded gasoline, but that is a whole other story..
https://www.motherjones.com/kevin-drum/2018/02/an-updated-lead-crime-roundup-for-2018/
ps: I am not saying that all paint fumes are as bad as gasoline..
but a lot of paints have Benzene or other aromatics:
“Benzene can be found in most all glossy paints, as well as spray paints and paint thinners.”
https://www.napolilaw.com/article/benzene-found-in-paint/
and according to wiki:
“most common aromatic compounds are derivatives of benzene”
https://en.wikipedia.org/wiki/Aromaticity
AFAIK benzene is not (much?) used in paints any more because it’s considered carcinogenic. Many paints are already water based, if this is not possible mostly aliphatic hydrocarbons are used as a solvent. If aromatics are really required, less toxic alternatives to benzene like toluene are used.
> does anyone know if there is NOx emissions from 100% bio-diesel/vegetable oil?
Yes, mode of burning is important here, higher pressures and temperatures are what matters for NOx emissions. Gasoline has NOx emisstions too, but that’s taken care of by catalytic converter.
and the normal three-way catalytic converter used on a gasoline engine won’t work to reduce NOx emmision on a diesel because diesel always run lean. that’s why diesel need to use urea injection instead
But if you inject too much urea relative to the exhaust volume, flow, temperature, composition… etc. then the catalytic converter turns it into ammonia and you get worse problems. Hence why VW used too little and tailored the software to only inject enough under known testing conditions when the engine load profile is controlled and the engine is known to be warmed up.
Yup, Nitrogen makes up ~4/5 of the atmosphere, doesn’t matter if the fuel doesn’t have any nitrogen at all, it is formed from atmospheric N² being cracked apart in at the high temperatures in the combustion chamber and then reacting with oxygen.
Sulphur on the other hand comes from the fuel, and that’s why ultra-low sulphur diesel is now a thing. It is also being removed from engine oils, along with zinc, to mixed reviews…
Bring back IDI
Running veg I once got pulled over for a “black smoke test”
I chuckled a lot at that but let them waste their time.
“… gasoline emissions are for the most parts not even acknowledged.”
Other than most places in the world where road worthiness and emissions testing is concentrated on petrol emissions?
and until recently the requirements for gasoline engines have been much stricter than for diesel engines
at least here they always talk about diesel emissions and particles in the news!
last time the news talked about gasoline/petrol was when they introduced lead-free.
just because there is regulations, does not mean that the problem is solved.
Uhm…huh?
Educate yourself before you make a joke out of yourself. You’re talking nonsense.
“paint fumes” the term you were searching for is PAC (Polycyclic Aromatic Hydrocarbons)
And for modern gasoline cars those are just a problem during cold start conditions, when the ECU will enrich the fuel mixture that even with condensing fuel on the inlet manifold enough fuel vapor is entering the combustion chamber(in case of indirect injection into inlet manifold, less problem for direct fuel injection).
During normal operation the catalytic converter will burn excess HCs also the ECU will adjust the amount of fuel added to the mixture using information from the oxygene senors (one before cat conv and sometimes one after)
But in today’s engines with the ECU control and high performance cats that is only a problem for a very short amount of time during cold conditions.
Not mentioning pre mid nineties cars.
and when doing the emissions test for approval the emissions during startup is included
In most places, not. I haven’t heard anywhere that does or requires cold crank emissions tests.
The NEDC has started with a cold (25C) engine since 1997: https://en.wikipedia.org/wiki/New_European_Driving_Cycle
WLTP is run at 23C but “corrected” to 14C.
NOx will be produced anytime you have a combustion with (excess) air at high temperatures. Unfortunately you need high combustion temperatures to get good thermodynamic efficiency..
Hack the planet?
Oh we’re hacking it alright. Rest assured of that.
I assume diesel and gasoline are both extracted from the same oil stream, in a proportion dictated by chemistry and distillation processes.
If all of a sudden many diesel consumers switch to gasoline, how would refineries be able to produce, from the same stock, more gasoline and less diesel?
That’s actually a very interesting point. The basic distillation process can not be altered to get more gasoline and less diesel since they’re both in there anyways and you need to remove the diesel to get gasoline in the first place.
And you can’t just use the other on a vehicle, gasoline in it’s fluid form is very light, volatile and “clean” (not oily or something, you can actually use it to clean stuff) so the fuel system is set up for that (finer injectors etc.), while diesel is fairly heavy, thick and oily, which is why diesel fuel systems don’t require any lubricant (specifically the high pressure pump).
Swapping them will screw up the engine either way, diesel in a gas engine will clog everything and hydrolock the cylinders while gas in a diesel will cause high wear on the fuel system and detonate in the cylinders.
Now the question is if it’s possible to “convert” diesel to gasoline by some chemical process.
The majority of crude oil is very long-chain stuff, close to what’s called bunker oil. Refineries distill out the small amounts of lightweight stuff (automotive grade petroleum, even lighter stuff) and separate out the weird stuff (napthas and other aromatic hydrocarbons) and then they thermally crack the heavy stuff down to diesel and petroleum and other industrial starting materials, in proportion to market needs. (And for auto petrol they then have to remix it to meet octane requirements for different markets, and in the US, this also involves remixing with various amounts of ethanol to financially subsidize Midwestern corn farmers in the name of reducing emissions.)
Soybean farmers too!
There are all sorts of chemical processes which can convert long chain hydrocarbons to shorter hydrocarbons. The processes are usually called cracking, and they are already done on industrial levels. I think diesel was only an output of a fractional distillation process, where petrol (or gasoline) is distilled and cracked.
If you have a refinery that is geared towards gasoline like in the US, you use a Fluid Catalytic Cracker which will crack the gas oil to gasoline mainly in a hydrogen deficient environment. This process generates lots of coke burn which when treated which is expensive and will generate a lot of CO2. This process also does not remove the sulfur and lower quality product. If you have a refinery that is geared towards diesel which is every other location, you use a hydorcracker that will crack the gas oil to diesel mostly in a hydrogen rich environment. This process will also remove the sulfur and creates a better product and uses less energy. So from producing the fuel with lots of other factors being equal, it is better to make diesel and you get lower sulfur and better quality. For same quality for gasoline, you need further treatment which is cost and other emissions.
Yes, that’s generally called “cracking”. There are different processes, some only with heat (e.g. hot steam) some with catalysts. But these processes of course cost some energy and money.
There’s this little chemistry magic called cracking…
How do you silence a green party member here in Germany if they complain about diesel engines?
You ask them how they want to enjoy ther “hass” variety of organic avocado delivered from Chile and other fancy organic fruit and vegetables to their overpriced organic supermarkets, if there are no diesel driven cooling engines for the cool delivery chain.
cool delivery chains and power grid stabilization and emergency power supplies as well as combined heat and power systems all rely on the diesel principle, and these are neglected in all plans about the “future”.
clogged filters? could be diagnosed in the motor electronics, much like any other engine state or parameter.
NOx? just mandate thet the engine has to stop if the urea tank is empty
Crookery in the car industry? Just jail the bosses and sell their houses and pension funds. f*ck them plenty in every conceivable way, they need it.
Oversized cars with oversized engines? just tax cars in ((power output) * (emissions) * weight) / passengers
I can remenber times when a “huge” car for the average family had abount 70-90 HP. No one needs a car capable of doing 270km/h 24/7 for standing in the traffic jam each and every day.
OTOH, nobody needs a electric car, which can not cope with 2*50km commute a cold day in the winter
On could make a little problem from a big problem by rightsizing, and almost no problem at all if engine manufacturers hab to deliver on certain features (“urea stop”, better diagnosis and mandated scenarios like only half power if filter is clogged as an incentive to visit a workshop. Also, mandating open standards and certifications, so that anybody can go to any workshop nearby to get the engines fixed, would help a lot.
Unfortunately none of this will happen. the greens want the diesel scalp, and it is an easy victim.
it is already done, the electronics diagnose and run regeneration of the particle filters and if the urea tank is empty the engine will not restart (you get a few 1000s km warning)
Why do you want to silence a green party member, all in all your arguments are in favor towards a green agenda.
And pointing out that an Avocado with such a huge CO2-backpack is just too cheap.
And btw. cars for 2×50 km commuting do exist and they are getting bought more and more, i3, E-Golf, Tesla 3, Zoe.
Well however we just need to hit on BMW for discontinuing the i3, because they want to SUV-Size their next electrical car, and they are not in for small cars!
There’s a bunch of local (German) politics embedded in @Peter’s rant. Basically, all of the parties are for legislation that would be seen as “green” in the USA, which leaves the Green Party no room but to go a little further out on the spectrum. While a lot of their policies are actually very sensible, sometimes the take the extra step to distance themselves from the mainstream.
So while the others are like “we need to shut down our coal-burning power plants by 2030” the Greens are like “we need to shut them down tomorrow.” That sort of thing. Some would say that as a minority party with a green mandate, making impossible demands is kinda their job. It rubs other people the wrong way.
But the diesel-based ideas are all mostly real. Look up Euro6 standards for diesel engines — they have tight regulations and and a lot of them use urea-based catalytics, have sensors for the filters, etc. This is all mainstream- to slightly high-end-tech.
VW et al were caught cheating b/c they wanted the cars to look sporty as well as clean, and you can’t really have both (with any fuel/power source).
There are tons of dirty diesel cars/vans/wagons on the road here, and that’s a real problem for particulates and NOx / smog, but the newer and more expensive diesels are actually reasonably clean.
(Disclaimer: we drive a Euro5 diesel.)
That’s correct. Also, the green party and green parties around the EU tend to be allied with the extreme left parties, and they see environmental politics as a means to implement socialism by the back door – hence why they make politics where any solution which solves the problem the wrong way (maintains consumer choice, free market capitalism) is unacceptable.
For example, rather than cleaning up private vehicles, make it impossible to own a vehicle in the first place, so you’d have to implement extensive public transportation schemes.
Also notice the double standards in the EU: passenger vehicles are regulated by CO2 or other pollutants per kilometer, while large commercial vehicles are regulated by the kWh – which means that you can be dragging a boat anchor through the streets and burning as much fuel as you want – as long as you’re doing it “efficiently”.
This results in the fact that all the vehicles that are used to haul goods actually produce comparable amounts, if not more, NOx pollution as all the private diesel cars – yet this is completely overlooked by the greens. For obvious reasons: the public bus they just took to get to their latest protest runs on diesel as well…
I do not silence the greens – they just have no answers and remain silent, reproducibly so.
If they had a realistic, feasable concept, everything would be fine for me. But they have not. This is mostly about virtue signaling…
They now are a green religion or sect – they want to feel better by imposing their abstinence regimes on others.
The avocado was only one example of the hypocritic behaviour of the green crowd, shiny drinking bottles of the season or white SUVs with “hybrid” written in chrome on them are others.
(FYI: I used to be a member of the bavarian section of the green party up to 2003 when they too started warmongering).
I had a Zoe, until the first winter. Not coming home just is no fun. Yes the car could have done it in theory, if I had noticed that the charger had an error and stopped during the day. Or the other Zoe driver occupies the charger… Or you are in a traffic jam, and the heating runs… Happened too often. The last 800m to my home have 13% inclination at one point, a steep bank of a river valley. The neighbors who saw me there won’t buy electric cars for some years…
Now I have a 58HP gas engine Clio, no A/C, at least it drives. Nope, I’m still not into huge, plushy SUVs. See, I used to be green, I have logged 14.5 years without car, with bicycle and railway, living at the countyside. I’ve ridden my bicycle literally through hail and storms, was in time at the station, only to find that the Deutsche Bahn stopped traffic “due to storm”. I’m almost 50 now, and sometimes the bones hurt, maybe I’m getting lazy a bit.
Due to construction works this summer I sometimes have ~20km deviation (two Autobahn exits closed, please use the third). With a conventional car this is only an anoyance. There is unfortunately no electric equivalent to a jerry can.
I’d be totally fine with a single seater Renault Twizy with doors and huge battery and 120km reach, it’s only commuting after all: go from A to B, dry and warm.
i3 – best window manager! Oh, the i3 car – don’t get me started about it. It is just like in GROWIAN times, when they seemed wanting to prove that wind energy just does not work. The i3 is in my opinion something similar for small electric cars. I was severely underwhelmed, even when compared to the e1 (electric concept from the 90ies which I could get some drives with during my study days).
Tesla: The early ones have “californian” rust prevention, we in the north of the alps have sometimes more salt than snow on the streets, in strong icing nights even salt moistened with urea.
The newer ones are quite okay.
But there is one thing which I just won’t buy: https://www.tagesspiegel.de/berlin/illegale-autorennen-berliner-polizei-greift-immer-haerter-gegen-raser-durch/24033226.html (sorry for german text) Tesla obviously logs speed direction and position in one second intervals. Well, *nobody* needs to know my speed direction and position, *nobody* needs databases about it. so I won’t buy it – easy as that…
Yes, unfortunately, after the first sentence he sounds like a greenie.
I want the greens scalp. :-) Hopefully the pendulum will swing back from this excessive environmentalist hype as soon as possible.
Can’t die fast enough. Every time I visit my parents in Bulgaria 80% of the cars on the road use diesel and emit copious amounts of black plumes every time they accelerate. Yet people loved to tell me how emission standards in US are crazy and the dieselgate was a conspiracy.
The “rolling coal” crowd is not helping the diesel case in the slightest. There should be civil penalties for such recklessness.
I can understand your disgust, however many people especially in eastern Europe on one side will drive older used cars which are sold from west Europe towards the east.
And some (truthfully I would say many) of your compatriots are known to have blanked ERG-Valves, manipulated ECUs, Ad-blue(c)-Emulators and emptied-out diesel particulate filters.
The intensity of those manipulations decreases towards west/north europe. It was done here too, however now in germany the two-year car and emissions check (TÜV equivalent of MOT in UK) ) the real exhaust is analyzed, that make it a lot more work intensive to undo the manipulation before testing and refit afterwards.
Prior to this year only the ECU was asked if everything was ok :)
So it has something to do with the economic environment also.
“and thanks to low volatility, diesel engines can run at significantly higher compression ratios without risking detonation.”
eh? No….
Diesel is self detonating under lower pressures compared to gasoline, if an oxidizer is around that is.
The reason diesel doesn’t combust within the high pressure fuel lines is due to the lack of an oxidizer.
It is however injected into the engine at the top of the piston’s stroke. (actually slightly after.)
When the diesel gets injected into this high pressure oxidizer filed environment, it will quickly detonate. (No real need for spark plugs, heat, or anything like that to be fair.)
This is the main reason you can’t put gasoline into a diesel engine, the gasoline won’t as easily detonate under pressure. (This is why gasoline cars inject fule when the piston is at the bottom at its stroke, letting the fuel-air mixture compress before the spark plug ignites it.)
It is two completely different ignition systems, and putting diesel in a gasoline engine will result in the diesel igniting during compression. (ie the piston hasn’t yet reached the top of its stroke. This will cause major engine knocking.)
Ethanol and Methanol on the other hand has even higher resilience against self ignition under pressure. (A good reason for why a lot of sports cars with high compression engines are using it.)
Though, I should probably add that a diesel engine can achieve higher compression then a gasoline one, due to injecting the fuel into a high pressure environment. This means that we never need to compress a fuel air mixture to start with. This is though also possible for gasoline engines too and is done on some cars. (And yes, if the compression is high enough, spark plugs aren’t technically needed yet again.)
The main problem of putting gasoline in diesel engines is mostly for engines with low compression ratios. If the compression is high enough, a diesel injection method can use practically any fuel.
You’re…semi-correct.
While diesel is self-igniting, it is not self-detonating.
A controlled ignition is what makes your car go, an uncontrolled detonation is what makes your car throw a rod or two.
The main difference lies in the speed of the two.
An ignition will burn just fast enough to push the piston down with force. Think of holding a stationary toy car, accelerating and releasing it, making it go.
A detonation will burn a whole lot faster, causing unnecessary stress on the piston, the rod and the crankshaft. Think of putting that toy car on the ground and smacking it sideways with a hammer to make it go.
You can’t put gasoline in a diesel vehicle, since it will start detonating instead of igniting. Also most diesel fuel systems use the fuel for lubrication.
And this is also a detail that I should probably have covered, thanks for adding this actually valuable information.
Then there is always the sterling engine that practically only needs a nice steady open flame to run, and can really run on practically anything that will sustain an open flame.Also burns at a lot lower temperatures, doesn’t really generate NOx, and also tends to extract far more of the energy from the fuel, resulting in far higher fuel efficiency. (60% would be fairly casual for them.)
Downside, they sure do not change RPM in any fast manner… But as a generator in a hybrid electric vehicle, it could probably be a fairly nice solution. Would only need to generate the average power consumption of the car (15-40 kW), while leaving acceleration and regenerative breaking to the battery pack and capacitor banks of the drive train to handle.
Stirlings are also heavier, and they’re limited in their power output because all the heat from the combustion (ideally) has to pass through the working fluid (gas).
If you think of a steam engine, there’s a condenser which takes the return steam from the pistons and blows heat out into the atmosphere to turn it back to liquid.
This same mechanism is present in a Stirling engine – you need a large radiator to exhaust the heat you couldn’t utilize before the working fluid passes back into the engine. Otherwise the effective temperature differential across the engine gets less and your efficiency drops to near zero. This radiator limits the amount of thermal power you can pass through the engine, which limits the amount of work the engine can do.
In a once-through steam engine, the hot steam itself is exhausted. This is equivalent to the internal combustion engine, which exhausts the working fluid out the tail pipe. If a Stirling engine could be made that takes in atmospheric air and expels it out the other end, no exhaust radiator would be needed and the power limits would be lifted. This is impossible, since the pressure and temperature of the working fluid is so high that the oxygen would start to react with the engine components.
Yes an old traditional sterling engine is typically a large cast iron beast. (a modern one on the other isn’t.)
But heat doesn’t actually need to “pass through the working fluid”. The changes in pressure throughout the whole enclosed working chamber is what transfers the bulk energy.
And in actual Stirling engines, we desire as little energy as possible to spread as heat. Since that would be a direct energy loss. This is usually achieved by adding “long”, usually well insulated pipes between the warm and cold side. Sometimes these are even having pressure chambers on them as well. This all is to increase the thermal resistance of both the working fluid and the chamber as much as possible, while still allowing for fast pressure changes in the whole system. (One downside is that these pipes can expand/contract a bit due to the pressure changes, and yes, this would mean an energy loss for the whole system. So generally they have a small inner diameters, and thick walls. Steel is generally a decent trade between tensile strength and thermal conduction, and one can also line the inside with ceramic or other insulators.)
Secondly, a modern Sterling engine typically works at very high pressures, compared to atmospheric. This also helps with aiding how much torque the engine will be able to give for a given size. (It is similar to how a gass spring works, fill it with higher pressure and it gets stiffer. rule of thumb)
Next detail would be the radiators, these wouldn’t actually need to be “gigantic”, but rather proportionally sized to the engine’s power rating, or rather what it has as a loss. Ie stuff in 2Kw of heat, have a fuel/engine efficiency of 60%, and you now have 800 watts of waste heat to deal with. (And considering that the “cold” side of a sterling engine still can be upwards of 50-80C, then a typical car radiator isn’t going to have much problem keeping said cold side within reasonable temperatures. Do note, the warm side can still be around 200-800 C, so one will still get the vast majority of the energy out of the fuel. I also hope people aren’t just skimming through by now…)
A more problematic source of efficiency loss of sterling engines on the other hand is the exhaust of the burnt fuel, a “typical”/simple solution is to have a two or three stage Sterling engine, where the first stage works on the fuel source directly, the next stage works on the hot exhaust gases, and the third works with the less hot exhaust gasses. (they all share the same temperature on their cold side, as to ensure the largest temperature delta.)
Though, one can add more stages at infinitude, but it has diminishing returns. Especially since a lower temperature delta means that it will extract less energy for a given piston volume, but one will draw a line at some point where the returns have diminished beyond practical limits.
One also needs to ensure that one isn’t blowing through too much air through the engine as well. This would result in the warm side not being as warm as possible. Here one could mostly rely on the stack effect, or just make a carefully adjusted fuel air mixture to start. Another even simpler solution is to make “the world’s longest exhaust pipe” coiling its way around one warm piston after the other, and then being wrapped in ample amounts of good insulation to not have the heat escape out into ambient air.
Also a quick note, the fuel for a Stirling engine isn’t its working fluid. So the statement: “If a Stirling engine could be made that takes in atmospheric air and expels it out the other end, no exhaust radiator would be needed and the power limits would be lifted.” Doesn’t really fix anything, other then make it abhorrently inefficient, if one gets it to work at all…..
The main downsides of Sterling engines is that they take a bit of time to get going. And they don’t really like changing how much power they output, mainly due to thermal lag of the warm and cold sides. On the other hand, it is practically perfect for constant power applications.
>”But heat doesn’t actually need to “pass through the working fluid”. The changes in pressure throughout the whole enclosed working chamber is what transfers the bulk energy.”
That is a complete misunderstanding of how any heat engine works. I’m sorry, but you’re simply wrong.
>”Also a quick note, the fuel for a Stirling engine isn’t its working fluid.”
That was not claimed.
The working fluid, the pressurized gas that circulates inside the stirling engine, carries thermal energy (heat) from the hot side to the cold side. The cold side of the engine HAS to be cooled down to remove the unused heat from the working fluid and expel it to the environment to keep that side of the thermal cycle as cold as possible.
This temperature difference between the hot and cold side is what maintains the efficiency of the whole cycle. This is how all heat engines work. Since a Stirling engine is a closed cycle, a heat exchanger, a radiator, is required.
In an open cycle engine such as the otto or diesel cycle, or with the open steam engine, the radiator is not needed because the working fluid is exhausted into the environment and it carries the heat away with it. Hence the cold side of the engine can be though of as being at the temperature of the environment. In a Stirling engine, the cold side of the engine is at the temperature of the radiator that expels the heat from the cycle. This is why the Stirling cycle is limited in power by the size of the radiator that exhausts the heat. When the radiator runs out of capacity, the temperature of the cold side starts to rise, the efficiency of the cycle begins to fall, and the power output becomes limited.
If you could build a Stirling engine that takes in working fluid from the environment – not the fuel but air from the environment – and exhausts it back to the environment, this limitation would be lifted, but as mentioned this is not practically feasible. It would work at low temperatures, but the efficiency would be poor anyhow.
“… these wouldn’t actually need to be “gigantic”, but rather proportionally sized to the engine’s power rating, or rather what it has as a loss. Ie stuff in 2Kw of heat…”
Consider that the actual efficiency of a Stirling engine is not 60% but more like 40% and less because the maximum efficiency is only attained at 100% output. Throttling down a Stirling engine drops the efficiency and with the peak power margin required for a regular car (70 – 100 HP), the engine ends up running at the lower end of the efficiency spectrum – unless you want to add insult to injury with generators, batteries, and electric motors in addition to the heavy Stirling motor to have a hybrid engine.
In practice, the existing trials with Stirling engines have achieved only 40-50 MPG fuel economy, which is completely in line with modern ICE engines. Only, the ICE can produce 200 peak HP while maintaining that average economy, while the Stirling engine struggles to top 50 HP.
Diesel IS self-detonating. The difference is that in a diesel vehicle the fuel ignites before the fuel droplets evaporate (low volatility), so the burning happens as if the fuel was small particles. This is the reason why you can run a (specially made) diesel engine on coal dust as well.
This also creates the other problem, which is the particulate emissions. Since each droplet of diesel in the engine burns from the outside in, it leaves a small soot particle when the oxygen in the vicinity of the droplet runs out. If the engine runs lean, the droplets burn completely, but when you increase the amount of fuel, some droplets don’t burn completely and you’re left with black smoke.
What if we had a double-cycle, “afterburner” engine? Get exhaust from primary cylinders, add controlled amount of air (more oxygen) if needed (if diesel burns lean, there should be unreacted oxygen present, and if I am not mistaking, NOx are oxidizers, too) and compress it again until it ignites and extract some of remaining energy.
@salec This sounds a bit like Exhaust Gas Rrecirculation (EGR) and (maybe?) the Atkinson Cycle.
The Atkinson Cycle is meant to improve efficiency by making the powerstroke longer than the compression stroke, either by a second cylinder or by not closing the intake-valve until the compression-stroke has begun. Find a video on youtube, as this is hard to explain in text. Engineering Explained has a good video on this.
The exhaust recirculation reuses the exhaust when the engine is idle, to either improve compression in gasoline engines (More air, but not more oxygen), making the engine more fuel-economic and thus improve emissions, and in diesels, it is exactly to reduce unburnt diesel and thus (again) improve emissions and fuel economy.
But this system of course reduces the engine power and because of the higher temperatures in the intake, it cannot mix too much exhaust since it makes knock(detonation) more likely, so it is usually only active at idle
Adding oxygen to the exhaust does not work because the expansion of the gas in the cylinder lowers the temperature to the point where it no longer sustains combustion. The soot kernels that didn’t burn, won’t burn because it’s not hot enough. That’s where the catalytic converter comes in – it catches the particles onto a screen where the particles burn like briquettes in a charcoal grill.
Though you need to get the catalytic converter hot for that to happen. In city driving, it doesn’t, so the ECU starts a regenerating cycle which injects extra fuel to generate heat and burn the particles off the filter, which increases fuel consumption and does a number on the emissions as well.
You are saying “Catylitic converter” when you mean “Diesel Particulate Filter”
Well, it is a -type- of catalytic converter. There’s a mesh screen that retains heat and catalyzes the burning of the particles.
Or more precisely, there is a mesh screen that retains heat WHICH catalyzes the burning of the particles.
Though the mesh is also composed of materials which lower the energy barrier for combustion of carbon, so they make the particles burn at a lower temperature, which makes it a catalyst in both senses of the word. Kinda like the silver mesh of a petrol powered pocket heater, or the screen of a butane soldering iron.
Again, incorrect. Try and guess why diesels have glow plugs and then rethink what you said about it not needing heat.
Compared to gasoline, one doesn’t need all that much heat to get diesel going.
But yes, more then room temperature is still needed.
And the glow plug is mainly there to supply some heat for starting the engine, primarily in cold/wintery weather.
But glow plugs aren’t actually “needed”, since the compression of the piston itself can make the air heat up sufficiently. But if the engine block is cold enough, it can suck away that heat and keep it from working, or starting on the first try. (But the electric motor used for starting the engine can potentially overheat before the engine starts when it comes to repeated attempts, not to mention the risk of engine flooding, so glow plugs is a cheap and easy solution. But yet again, this isn’t true in warm weather.)
And I should probably add that a petrol driven engine will never start without a spark plug.
Since the compression won’t ignite it, nor will the pathetic amount of heat generated from said compression. Not even the running temperature of the inner lining of the cylinder is enough to ignite it either. (And this is by design, otherwise one will have some serious engine knocking.)
Don’t forget hot bulb engines, which operated on the principle of dripping fuel onto a hot piece of metal inside the cylinder, heated by previous combustion cycles. These could operate on gasoline as well, although it was mainly designed for diesel-like fuels, kerosene, vegetable oil etc.
Gasoline Engines do not have the compression to ignite diesel. Even if it does, its not going to burn sufficient amounts to induce knock.
At best, you’ll get some smoke as you try to crank, but no actual function of the engine.
Diesel Engines ONLY function because of being high compression (19:1 atmospheric) versus Gasoline (9.0-11.0:1 compression)
Given the superior power claims of dirty dieselers, it’s remarkable that they have such limited motorsport success.
I guess that the problems are power delivery and reliability.
Superior torque. You need high hp for race engines and light weight. Unless your race is a tractor pull or mud bog osomething like that.
You seem to have a bit of a misconception about power. If you have a given horsepower, the difference between torque and speed is simply transmission gearing. If you have really high horsepower you can just have both. Power in the context of an engine is essentially a product of torque and RPM. You can make a gas engine put out the high torque of a diesel with a lower gearbox.
Kind of like how power in electricity is a function of voltage and current. In this context, voltage is the analogue of torque, current of RPM, and horsepower would be represented by watts. Which in fact is also what horsepower should be measured in. Nobody should be measuring with horses anymore. But that’s a different story.
Close but not quite! Horsepower is the equation of performing work in time over distance. As in move something of a given weighting a given time. Do it faster and you more hp. Torque on the other hand is the ability to apply a force over a distance. Time has no value. The trade off is of course rpm. Diesels produce large torque at relatively low rpm 1000-2000 commonly usually 1350-1850rpm in highway tractors, pickup diesel like dmax @1600rpm. Gas engines produce peak torque from 3400-4800 commonly. Through gearing torque can be gained through proportionate speed reduction. yes.but acceleration is lost almost entirely.
Difficult to win with a Diesel engine when the regulations limit the fuel to a specific blend of gasoline. But where it’s not impossible due to regulation, its possible to do pretty well. See Audi R10 (https://en.wikipedia.org/wiki/Audi_R10_TDI) at Le Mans.
Rolling coal is purely a byproduct of over fueling. Rarely does someone make a tune for the sole reason of rolling coal. Its often most visible at the begining of acceleration when turbo chargers are least effective and supplying the least boost. Resulting in a larger amount of unburnt fuel coated in soot ie a black cloud.
Race trucks often are particularly bad due to additional injector inefficiency at low speeds. since larger injectors perform poorly at low injection timings.
well designed tunes for trucks with intact emissions systems will not do this. since your only increasing the regen rates and potentially poisioning the dpf filter. the biggest drawback to after market tunes in diesel trucks.are that your rapidly increasing wear snd tear on your engine and transmission. Most diesel trucks in the US will average in the 350,000 mile range.and are often kept on the road for close to 20 years. In comparison to gasoline vehicles which require more service and often have much shorter life spans before removal from the road. More in the range of 150,000miles.
People are deliberately modifying their cars to overfuel hence roll coal. Which includes DPF-Deletes.
A common “trick” to roll coal is a plastic bag over part of the air filter, or so I hear. Starve the engine of oxygen, get excess fuel. Presumably people doing that really are doing it just to make clouds of black smoke…because…reasons?
Electric cars have gobs of torque, easily comparable to pickups. In my experience, pickups towing trailers usually have very little in the bed, so I’m thinking about a conformal battery package 40cm deep that includes BMS and active cooling, that can be forklifted into the bed of a truck and give it huge range. I know people who would be markedly more likely to buy a truck set up like this, just so they could take up two supercharger spaces, one for the internal battery and one for the bed battery. (They’d have to be set up on a common bus to get the bed battery power to the motors, of course, but it’s easy to set them up to provide for electrical separation during charging.)
Not directly related, but I saw a video on Youtube a while ago about a Reactivity Controlled Compression Ignition (RCCI) engines which use diesel fuel as the ignition agent for a diesel/gasoline mixture. Apparently it gives most of the efficiency benefits of diesel while significantly reducing the emissions.
https://www.youtube.com/watch?v=pCr6bjQMrgU
But its still a follow through Oto Movement ..very inefficient..
“Pilot injection.”
Maybe, but not for decades and the change will be fairly slow. Our economy moves on diesel trucks and they are not going to vanish overnight.
And diesel ships…
Rudolf Diesel ran his engines on peanut oil (as well as coal dust), so the petrochemical industry calling their fuel Diesel was an advertising master stroke.
Is the N in Nox just from atmosphere?
How much compressed oxygen would you need to make a diesel car usable?
What would the emissions be then?
Uh not sure what you mean there. The nitrogen and oxygen both come from the atmosphere. The higher heat and compression ratio just combines them into N₂O, whereas in gas engines there isn’t quite enough pressure to make as much apparently.
If you used compressed oxygen, how would that change the exhaust? You’d presumably be getting the oxygen from the atmosphere anyway, just putting it in a tank in between. And the exhaust is still going out.
Also: you would need a ludicrous amount of oxygen to run an engine. You’d basically need a cryogenic system and liquid oxygen—like a rocket—to go any useful distance. Combustion engines consume lots of oxidizer.
NO2, not N2O. One is toxic, the other will make you laugh.
Yes: NOx is shorthand for nitrogen bonded to various amounts of oxygen, usually NO2. (You can also get N2O or NO but they’re higher energy, so are produced in much lower amounts.)
The problem is precisely that there’s too much oxygen, because you’re burning lean, hence hot, active oxygen breaks nitrogen down. No amount of adding oxygen is going to do anything but make it worse. A solution is to burn richer, so you use up all the oxygen, but that’s basically a gasoline engine. Much of the point of using a diesel engine is precisely that it can burn lean, and give you high efficiency. A low-NOx diesel isn’t competitive.
I guess John’s idea was to have a vehicle that uses pure oxygen from a tank instead of taking in any air. Since the pure oxygen in the tank contains no nitrogen, this setup would eliminate the NOx problem of air breathing diesel engines.
The stoichiometric ratio for a diesel engine is 14.5, you need 14.5 kg of air to burn 1 kg of diesel fuel. Since only the oxygen is part of chemical reaction that drives the engine, you should be able to replace those 14.5 kg of air with 3,36 kg of pure oxygen (air oxygen content by mass is 23.14 %). So to burn the 50 liters (= 42 kg) of diesel in a car’s tank you would need to carry 141 kg of pure oxygen.
Perfect reply, cheers.
So, given the amount what is that as a volume at a typical pressurised oxygen tank pressure?
Plus the tank weight needed at that pressure obviously.
It doesn’t seem to be unreasonable.
A No.5 welding gas cylinder (51″x9.1″) weigh 114lbs and holds 251cuft of oxygen at 2200psi. That’s about 10kg if oxygen. Keeping 14 of these bottles does not seem very practical.
Now you could get much better storage density with liquid oxygen but good luck getting type approval for that.
Fine, stop making diesel passenger cars and light trucks. Commercial vehicles will be exempted, the price of older diesel trucks is already rising. Workers need work trucks and can’t afford any of the new stuff.
I’ll be eligible for agricultural exemptions, but am already looking towards growing and making my own biodiesel.
Since all the experts are gathered now:
1. Do coal-fired (or natural gas) power plants have this NOx problem as well?
2. What about old-style steam engines of Watt type, or later?
3. Plain wood-fueled fire?
Thank you.
1) yes, however natural gas plants don’t run at such high temps, so the NOx emisions are far smaller
2) power to weight and efficiency…reciprocating steam engines suck badly in this department
3) soot, ash and tars…just…no. Convert wood to methanol, use that, either by burning or in a fuel cell.
Thank you.
Re 2), it should be possible perhaps to avoid fire for heating the boiler with water, and just use concentrated sunlight.
Re 3), clean methanol burning is not producing NOx?
Nothing like a bit of diesel hatin’ to get the juices flowing. I absolutely love my diesel Jetta. I kept it throughout the scandal, refused to trade it in and will keep it running for as long as I can. The fact that they wanted to take it from me just gave my “anti-establishment” mindselt an outlet. Plus, it’s great on fuel.
They’re certainly great from a driving perspective, based on how many fans the VAG cars have.
Just a question about particulate emissions, those DPFs look like a pretty crappy solution, couldn’t they instead use a type of cyclonic filter to clean the exhaust stream, you know like a Dyson vacuum? Just an idea.
The biggest problem with ICEs (all of them) are the total efficiency of the system, from the sunlight coming to the earth surface to the energy used for moving vehicle.
All of our energy comes from the sun one way or another (beside nuclear, but that’s another story)
“A fossil fuel is formed by natural processes, such as anaerobic decomposition of buried dead organisms, containing energy originating in ancient photosynthesis” https://en.wikipedia.org/wiki/Fossil_fuel
“A fossil fuel, petroleum is formed when large quantities of dead organisms, mostly zooplankton and algae, are buried underneath sedimentary rock and subjected to both intense heat and pressure. ” https://en.wikipedia.org/wiki/Petroleum
The diesel or gasoline efficiency starts with efficiency of the photosynthesis, which is at best is 2%, but average 0.1% (!!!)
https://en.wikipedia.org/wiki/Photosynthetic_efficiency
The biofuels best claim is around 0.3%.
On the other hand
Water turbine Gravitational to electrical up to 90% (practically achieved)
wind turbine more than 30% ( up to 59% (theoretical limit)
Solar cell Radiative to electrical 6–40% (technology-dependent, 15-20% most often, 85–90% theoretical limit)
https://en.wikipedia.org/wiki/Energy_conversion_efficiency
So depending on the technology getting energy in form of electricity can be more than 100 (!!!) times efficient than getting energy from chemical fossil fuel.
That’s the start.
And converting to kinetic energy the average combustion engine is around 30-40% while large electric motors are more than 80%- (closer to 90-95%). There is a little loss with electricity storage lost in the battery is around 80-90% (Liion). But all the electrical to kinetic is more than 2 times efficient than the chemical (fossil fuel) to kinetic conversion.
(I did not counted in other factors like regenerative breaking etc. which is also makes the electrical motor vehicle more efficient)
And by the way combustion engines produce a lot of harmful chemical gasses (Co2, Nox etc)
Thanks, Andy.
Don’t forget naturally aspirated engine have lower volumetric efficiency, as well heat loss is upwards of 60 percent, ( heat differential- expansion of gases is the fundamental loss and theory of use…. Far better yet would be to extract hydrogen strains from wells, by injecting oxygen into them collecting and recombining in a Ballard fuel cell to produce elect and clean water. If abundant and cheap aluminum and magnesium were available sea water could be used as a catalyst in a stainless container where by plates of Al and MG are suspended In salt brine and connected as anode and cathode to produce electrolysis breaking down into hydrogen and oxygen, send said gases into a Ballard fuel cell and once again clean water and power. Oh wait thats a de-salination plant and power plant in one.!!!!!
It ist good an in true hacker tradition to discuss any topic.
But please provide figures which are comparable among each other: this article lacks a lot of them, albeit using comparative words (i.e. “more than” “less than”) without providing references at all or even direct useable base lines.
The comments catched up what I would have expected from the article!
Then: it is moot to argue pro or contra diesel/gas/electric/whatever, the cure ist to do less miles all in all.
If miles are unavoidable to be done, attempt to do ’em on a vehicle which ALREADY hast to run ’em!
The easiest and BIGGEST increase in efficency of a vehicle is the addition of it’s first passenger: the bump from transporting 1 bloke (the driver) to 2 lads (driver+1st passenger) is by +100%. The subsequent (3 vs. 2) just +50% and every subsequent step halves its bump in effiicency…
Actually vehicles should be taxed by UNUSED transportation capacity, trip by trip…
I think it’s just me, but I feel like a lot of current articles are written more with the intent of shaping outcomes rather than reporting them. This is the first I’ve heard of Diesel being on the chopping block in the United States.
I didn’t get to finish: I mean a lot of articles on Hackaday. I’ve been reading stuff here for a number of years, and now I feel like this is just another environmentally driven stage for morally beating anyone who doesn’t subscribe to the current Zeitgeist of Globalism.
This used to be a place where you could come read a great article on a new processor, a new hack for a device that would be thrown away otherwise, or some new tools. It’s not the same here anymore.
It’s just a reflection of the times. You can’t have any media that allows for an escape from what you get force-fed from other sources.
Atleast 2 of the best new tech diesel engines sadly never made it to market..Variable compression auto fuel mixing..sleep idle..high computer integration..the top engine has only one internal moving part..
Poor guy, getting morally beaten and force-fed. Awww.
Like it or not, the environment is going to become a very uncomfortably relevant subject in the next several decades.
Stating opinions, or one of many possible solutions to a problem as fact – or as the inevitable outcome -doesn’t make those opinions or solutions any more correct or likely.
I’m not sure why people think there is only one solution to our problems, or why the group-think of a large portion of the internet assumes that if you don’t tow the line on some particular solution that you must be an evil person completely on the other side of the issue.
I think it’s more toward moving the population onto mass transit, rather than personal choice. On mass transit, they can pump more people full of propaganda. Subject them to a dependency, for which they must pay as much as the regulating body dictates, or walk. Increase on petty crimes, since you can’t keep a tight hold on all your groceries the whole trip, you job tools (briefcase, laptop). Surprised Joe Biden isn’t a huge fan of mass transit, lot of people in reach, and no escape his busy hands… Mass transit isn’t exactly hygienic either, you get to share tight quarters, likely several with communicable health issues. Cold and Flu season wouldn’t be a fun commute, but there are some very serious things floating around as well. Independence and personal choices are the enemies of socialism, everyone needs to be on the same page, obedient, well controlled.
Diesel is king, and not going away anytime soon, it does the heavy work very well, and not easy to replace with ‘green’ solutions. Going electric everything, is going to mean increasing production tremendously. Lot of areas barely keep up with peak demand as it is. Electric cars might be ‘trendy’, but useless if it costs a great deal to charge. Demand drives the price, and renewable electricity is going to come at a premium price. Not many places get to chose where the get electricity from at home, single source sets the price. This whole ‘green’ thing is a political power grab, little to do with environment or climate. The vast majority of the activists promoting it, practice very little of what they preach. Usually some of the biggest individual offenders.
Toe the line …
Drink the Kool-Aid. Global warming cherry and climate change grape. More flavors coming. At least pretend you did or a nice frontal lobotomy so dont get ostracized. Some nice synthetic urine will fix it anyway.
Diesel isn’t on the chopping block in the United States. Cars are.
Which is why they’ll force manufacturers to reduce the already tiny amount of emissions from already regulated diesel cars at enormous expense (to the point where manufacturers think the risk of cheating is worth it) while they let commercial transportation continue to truck cargo around in trucks with visibly filthy exhaust with no penalty.
It’s pretty clear, especially in California, that the priorities are first revenue, second chipping away at car use, and third (or maybe lower) air quality.
Nail on the head sir
It’s a thing.
https://jalopnik.com/volkswagen-wont-sell-any-diesel-cars-in-the-u-s-for-20-1787311637
https://jalopnik.com/bmws-diesels-face-an-uncertain-future-in-america-1829004416
Washington big wigs put out more pollutants than diesels
Diesel fuel wont be dying out any time soon. The fuel is still a bi product of making gasoline and other oil based products. Even if they tried to stop desel sales the fuel will always be around. Reason is equipment and consumer transportion of goods. ( dont for get trains are still diesel as well).
Well, I think Warren Buffet, (railroad magnate) was experimenting with running his trains (e.g. BNSF) with coal dust from his Wyoming coal mines.
I will confess that when you are driving behind a diesel vehicle you can smell the toxic fumes that expel out of the tailpipe. I can also sometimes smell it with older gasoline vehicles but it is very rare. The new vehicles out there today gasoline vs. Diesel there is no comparison that diesel vehicles are spewing out toxic fumes. No I’m not a fan of gasoline as a matter of fact I hope that goes away as well. After driving electric vehicles and working with some heavy-duty electric powered vehicles there’s no comparison. There’s nothing like pushing down the Gas a certain amount and weather you go uphill or downhill you don’t have to push the accelerator pedal anymore. With the electric motor you get a hundred percent of the torque capacity from the first Revolution to the very last and its highest Revolution. An absolute pleasure to drive. It makes driving a gasoline or diesel powered vehicle archaic. The other big concern with driving a diesel vehicle is knowing that maybe someone’s or possibly your daughter is driving behind a diesel-powered vehicle and she is possibly pregnant with your grandchild or someone else’s grandchild. That human and the human that is being born within has to breathe in those fumes. Totally uncool! This is not a politically left or right comment it is just a common-sense comment that if we can get beyond our prejudiced we will see a true and how archaic using fossil fuels to propel really is. Think about it…we could send a picture Across the world with a small handheld device. However we are making wealthy and morally corrupt petrochemical companies even more wealthy at the cost of our lungs. Oh and just wait what really happens from pumping all this oil out of the ground as the water tables below us become contaminated with new elements because of all this drilling! I hope for a better future for all to inhale!
Before you publish play the devil’s advocate and assume that you are wrong, then go looking for proof because chances are you will find something that will help to balance out your work.
e.g. https://spectrum.ieee.org/energywise/energy/fossil-fuels/dieselpowered-fuel-cell-produces-green-electricity
If they keep posting these opinion pieces, it’s Hackaday’s future that’s on shaky ground. This is just bait to start a comment flame war so people keep arguing and increasing ad revenue.
Yeah, I was hoping this flame bait stuff was going to subside shortly after BB left.
Ducted fuel injection (DFI) has been recently discovered by Sandia National Laboratories (search it on YouTube). This could breathe new life into diesels for sometime to come. It will take a while before it finds its way into our engines though.
A quite remarkable planet. It’s been sequestering carbon on it’s own way before us as oil, coal, and frozen methane. Balance has been maintained such that we have a rather narrow range of planetary temperatures in three zones. Cold at the two poles, and warm the rest of the planet, allowing for liquid water to be in abundance. Animal life taking in O2 and exhaling CO2, plant life taking in C02 and giving off O2, and nature on it’s own sequestering the excess carbon as oil, coal, and frozen methane through natural processes. Mother Nature has done well… but we’re battering and bruising her pretty good these last 150 years.
The environment was good for life allowing even such as ourselves to evolve. Everything sustainable. Then we discover the coal and oil holding all that carbon and find it is useful and it aids our labors, gives us comfort, and provides a launch into an age of expansion with relative luxury and even allowing that we have time to educate ourselves and achieve higher learning, developing ways to better exploit the resources. Supposedly getting smarter we even reach the moon. It’s great at first, but we’ve reversed the natural process of carbon sequestration and just spew the excess carbon directly into the atmosphere as CO2 waste. This is at the same time we cut down the forests that have been sequestering carbon for the whole planet.
Methane is pure global warming gas on steroids. There’s a lot of methane on the planet sequestered by nature in frozen form, the planet has had all of history and prehistory to build up massive deposits just like oil has. Go look it up. It’s at bottom of oceans and underground. It takes just a physical disturbance or SMALL warming to trigger an entire deposit to suddenly phase change back to gas, and examples of these have already been reported more than a few times through history. Current day, for comparison, it was not long ago we’ve even been disturbed by how much cows fart as part of the normal digestive process because it is this same global warming gas, but all animals vent some.
A third world design exists to take human waste and use it to create methane for use in cooking. Mother Earth News long ago also did an article on it.
Ever think all that sequestered carbon would eventually leak out on it’s own, in large quantities, eventually? Methane is naturally produced by bacteria, when most anything dies and rots. Oil seeps up from the ocean floor, naturally, sometimes large enough quantities, to make people wonder about a ship sinking, or oil spill. Chunks are found in the beach sand all around the Gulf. We need CO2 in the atmosphere, was getting into short supply, before we started burning fossil fuels. Plants stop growing around 170 ppm, and starve around 150 ppm. If you had noticed, all living things are based on carbon, and that carbon only comes from plants. Plants are the only thing pulling carbon out of the environment. No plants, no food, for anything. Oddly, plants do very well with CO2 around 1,000 ppm, and like warmer climates best as well. Environmentalist aren’t really good for the environment. They have a little different agenda, which sometimes helps a few critters, but usually at the expense of something else and, usually the taxpayer.
Basically, drawing down CO2, until plants barely survive, is going to kill off a lot of the larger animals, due to lack of food. CO2 levels will slowly rise again, overtime, naturally, and it all starts over again. Dead plants dry out and burn pretty easy (ask California). Burning isn’t the only natural source of CO2 either. Volcanoes produce vent quite a bit as well. Our burning fossil fuels is actually holding off mass starvation, actually increasing plant growth, with is food for everything. Starving people are easier to control and manipulate…
We are intelligent enough to know what to do…
… but not smart enough to do it.
Diesel engines can run on cooking oil with very little pollution so if u can produce a good quality oil say from hemp seed u would not need the petrol station now would you, seems like someone will be loosing a lot of money
running on cooking oil makes very little difference on the amount of pollution, it just changes where the CO2 comes from
Yes, but when you are following one of those vehicles, your mind is on French Fries, instead of, “I’m stuck behind this stinky diesel”!
B^)
The subject seem to bring up a lot of argument, let met add some facts to the mix.
Diesel engines outputs less CO² than Gasoline. It is on the same level of emission as a properly used hybrid (gasoline/electric) motor. (As it recently turned out that as a whole, hybrid motors tends to burn more gas than regular motors, because of improper use cases, aka highways).
Diesel engines are stable and resilient and last longer (~+20%) thanks to their lower rotation speed. The downside being a higher cost to fix when there is an issue, because of its compression.
The only reason Europe is giving up on Diesel these days is because of politics. The NOx emission have been shown to be fairly bad on health in an enclosed environment, such as a busy city, and the filters were mostly inefficient in such cases (cold cars, low speed, small distances). But what has not been taken into account is the impact on CO² emission, which have increased because of this, and the fact that technologically, Diesel engine still have a long way to go. there are pattents, there are improvements that were unearthed of late, showing that with the proper opportunities, industries can fix a lot of these issues rapidly.
But peoples already linked Diesel with pollution, and government is taxing it hard. Peoples know they will have trouble selling their car if they buy one, so they don’t.
As a side note, NOx is only a small part of the particles emitted in cities. The biggest source coming from brakes. It makes a kind of micro dust that is particularly bad, especially in confined environment, such as underground trains and parkings.
So yeah, we’re in a “Solar highways” kind of political situation over here.
Also, expect some more scandals in the future, when politics decide to ban subways instead of upgrading it~
I agree that it looks like the technological solutions for diesel are very near. Filters, catalytic converters, etc. As the dirty cars/trucks/vans get pulled off the streets, things will get better. Euro6 standards for diesel and gas are comparable, which means that all diesels since 2015 are pretty clean.
BUT, and here’s where it’s not just “political”: some cities have dangerous levels of particulates and NOx, and they need a quicker solution. And that may mean putting restrictions on the oldest/dirtiest diesels until they move out of the system naturally. Add in the diesel scandal where some of the “clean” cars turned out not to be, and things get complicated.
I don’t know if the law changed, but when Colorado enacted diesel vehicle smog testing, the law required that 15% of vehicles fail every year. (I know, my diesel failed its first test). Part of the reasoning was to get the worst polluters fixed, or off the road.
I know there was a “gray market” of special fuels/additives one could use to get higher scores, it usually involved two tankfuls, with the second tankful you went to the testing facility.
But then, fixing or removing the worst 15% each year is a sliding goal. Did it stop? or were levels that were
“Pass” then now “Fail” as the worst keep falling out the bottom?
imagine a really easy way to start a class action against people, sort of like a microtort, where you get a bunch of people whose property (including their bodies) is damaged by emissions. Then sue each individual pollution emitting vehicle owner in turn, with the damages going to fix the harm done, and if the vehicle owner is offsetting somehow, they don’t have to pay.
Add in legal fees, cost of hearing the arguments in the court system, etc. and you pretty much understand why laws and regulations exist. I.e. to avoid all of this inefficiency.
Cut out all that by automation. Even better, use lots of buzzwords like blockchain and distributed technology. Connect it all to an app and you don’t even need to involve the courts and constabulary (providing of course there’s a common payment system in place, maybe motivated by a discount scheme, like 2% off groceries)
What about the AdBlue exhaust fluid that Mercedes Benz, VW and others are using.
Is it any better?
Surprised it is not mentioned in this article. It is not new.
New diesel cars are hitting the very low emissions levels of Euro 6 temp, while also delivering important CO2 benefits; there is just not that many on the road yet. The implications of consumers not buying new fuel efficient diesel or even petrol cars is evident as European CO2 emissions have increased for 2 years in a row https://www.eea.europa.eu/highlights/average-co2-emissions-from-new.
Given the energy density of diesel fuel it is likely to play a dominant role in the foreseeable future of goods movement and heavy machinery. Many tradeoffs at this time for competing fuels and technology. Particulate filters and SCR systems are not infallable but these are working as evidenced by the near-zero emissions performance of the new commercial vehicles and diggers. Meeting the dual challenge of preserving the climate and cleaner air requires many approaches. Imagine a diesel engine not running on diesel fuel at all but renewable diesel made from waste food processing or waste animal fats. this is happening today.
Good luck with that 300k mile cost overhead with gasoline with the freight industry which DOT allows to move 80,000lbs per truck.. To get 800-2500 lb-ft torque out of a gas engine requires rapid wear using high octane and forced air even after you put a lot of gear ratios with it..
Please no automated trucking comments either; we are at least a couple centuries from getting non-interstate “self-driving”/hacked-lane-assist just on dummy-license stuff..
“Diesel engines are typically poor when it comes to power to weight ratio,”
ROTFL
try the same calculation on electric cars
the usual nonsense when trying to demonize a fantastic, superefficient engine.
Tesla has shown that EVs can easily have a very good power to weight ratio. In fact, at present, range is about the only thing EVs aren’t good at compared to conventional vehicles. And thus why I think plug in hybrids would be the norm for the foreseeable future.
What if EVs could be temporarily converted to plug in hybrids by adding a generator trailer as needed? Then the extra weight of the generator wouldn’t be a factor in daily driving, only long distance travel.
Whew. Long thread. Sorry that the deniers came out.
The answer to less vehicular pollution in cities is less driving and more car-pooling, ride-sharing, and alternatives like public transit, trains and bicycles. For many reasons, the use of personal vehicles in cities must be reduced. Cities are for people, not automobiles.
There are still use-cases for fossil fuel; it still offers unmatched energy density. We just have to be better at recognizing utility vs vanity and selfishness, and using sustainable and less-pollutiing alternatives wherever possible.
Diesel has another advantage over gasoline – it’s much safer to store and handle. Spilled gas in a confined space is much more explosive than diesel. This makes it preferable in applications like boats.
Thanks. Very much appreciate your response. Diesel or gasoline: we have to use far less of either and both for this all not to become a moot point for the next generation. I’m converting a sailboat from diesel to electric, and beginning to shop for an electric car. But I’m not going to protest against the use of aviation fuel to get across the oceans, or the use of diesel to ship my groceries by train or truck. And we might all get a clue from Jeff Bezos who recently announced that Amazon will buy 100,000 all-electric (battery only) delivery vans from automotive start-up, Rivian out of Michigan.
FWIW I haven’t seen much “denial” here, it you mean climate change denial. (of course, you might not mean that)
I agree with you, the sooner I have no job the better (for everyone else), But in the meantime we can still try to make diesel (and petrol) engines as clean and efficient as possible as part of the solution.
There is enough here. Not that hard to spot.
I believe that diesel still has applications and a future; I expect that you will have a long and successful career.
I got a LOT of problems with this article:
1. Diesel does NOT produce more CO2. It produces more NOX, which is easily dealt with via Catalysts and DEF/DPF/SCRs.
2. Diesel is FAR FAR more efficient than gas, even compared to newer gas motor systems like Direct Injection
3. Despite dieselgate and all the fraud (which I fully admit that VW was rightly guilty of and deserved to be punished), VW/Audi bought back the cars, and now the TDIs are selling like hotcakes again. People WANT diesel efficiency.
Here’s the real problems with diesel:
1. They are far better at highway than city driving. Most of the Diesel Emission systems NEED highway driving to function properly. If you are primarily a city driver, diesel is not going to do it for you. Try electric.
2. The DPF/DEF system needs to be properly maintained to function properly, unlike a Gas car’s Catalytic Converter.
3. The cost of DEF of course (Diesel Emissions Fluid)
Diesels big environemtnal problems:
1. NOX is a major contributor to Smog and Acid Raid. Very bad
2. Jackasses removing the emissions systesm
3. People dumping soot through improper tuning (AKA Rolling Coal). Its wasteful, bad for the environment and their engine, and its pathetic.
Diesel is still by far a better fuel than gas, and it’ll be around for a long time
The other problem is the claim that “Power to weight ratio is low”
This isn’t really true. Yes, Horsepower suffers, due to the ignition cycle of diesel.
However, Diesels produce more torque, and in a better range than is gasoline brother. Power wise: Its far more. And torque does the actual work, not the Horsepower. And diesels have torque in abundance.
Few engines have the thermodynamic efficiency of diesel, gasoline still can’t touch it.
60% of the replies here are arguing CO2 volume vs mass emission. This isn’t 2005. The (primary) problem with Diesel is NOX emissions, which on the road were (during Dieselgate) found to be upto 40 TIMES more than the legal limit.
I’ve had tons of diesel cars, including the bi-turbo 3.0 BMWs, and two V10 TDI VW’s. Yes they were fun in their own way but they aren’t the forbidden mystical solution to everything I see purported in US forums. They have one trick (a sudden punch of torque) and the MPG in reality wasnt that much better.
The only conspiracy here was the documented and accepted one perpetrated by a handful of car manufacturers on the public.
Rudolf Diesel himself must be spinning in his grave (or the ocean floor where he mysteriously died..), he designed the compression engine to run on vegetable oil on farms to allow energy independence for the farmer via reusable/waste farm product.
Then the world found cheap oil, centralised its refining and distribution and the here we are.
It’s done, just move on.
I love this site!
yeah right.
never mind all the trucks and road trains.
let’s use that fancy tesla truck.
With all the advances in diesel-engine technology, diesel engines still remain louder thanks to the way the fuel is processed and the manner in which the fuel provides energy. Class 8 trucks are often noisier because the maintenance department sees the lead lined mud flaps that hang between the engine and the frame and various other engine shrouding as an impediment to maintenance procedures. These items are left out after the first service.
Actually diesels have much lower CO2 than petrol, which is one of the reasons they were pushed so much in Europe. The lower CO2 is in part due to the fact that diesel is a thicker fuel so burns less cleanly, particularly at lower temps. This means that instead of the fuel burning fully to CO2 and water vapor, it ends up burning ‘incompletely’, creating various oxides and particulates (fancy terms for what people used to call soot back in the day).
You started off with a true fact, and then presented a fallacious explanation.
The high NOx is due to the very high combustion pressure/temperature compared to gasoline engines.
They only make soot when tuned for low NOx, unfortunately it is a straight trade between the two.
all this discussion with people making reference to EVs / tesla this / green that…
um, we all do realize that the metals in those EV batteries are of a fixed resource exactly like fossil fuels. when the mines stop producing, its done. same for oil pumpjacks.
ford motor company said recycling EV batteries is cost prohibitive. meaning, it wont happen in the corporate world. guess once these batteries wear out, add ten years till we start seeing all those metals & chemicals in our water table. fun.
had a 2014 vw passat tsi (petrol) that got low 30s mpg on long road trips. have the exact same passat (inc wheels & tires) but the tdi (diesel) model that got upper 40s mpg on same trip.
realize this must scare people but lookup the vw dieselgate fix pdfs for ea189 & ea288 engines. find the EPA datatables for emissions before & after the fix. read the footnotes. EPA & CARB combine several fields for emissions after the fix. if one is educated, do the math on paper. these engines pollute more AFTER the fix however now they get half the mileage & expected lifespan has beem cut in half. funny that.
think people, some of you must still be able to problem solve on abstract data.