Mazda Investing Big In Advanced Gasoline Tech With Skyactiv-X

Electric cars, as a concept, were once not dissimilar from the flying car. Promised to be a big thing in the future, but hopelessly impractical in the here and now. However, in the last ten years, they’ve become a very real thing, with market share growing year on year as new models bring greater range and faster charging times.

With their lower emissions output and ever-improving performance, one could be forgiven for thinking that traditional combustion engines are all but dead. Mazda would beg to differ – investing heavily in new technology to take the gasoline engine into the next decade and beyond.

The Best Of Both Worlds

Mazda have offered diesel engines across their range in recent years. Image credit: Mazda

The holy grail of efficient combustion engines lies not with petrol, but with diesel engines. They routinely hit thermal efficiencies of over 40%, compared to the typical automotive gasoline engine which comes in closer to just 20%. This all comes down to the low volatility of diesel fuel. This enables diesel engines to run at very lean air/fuel ratios and incredibly high compression ratios, without the mixture prematurely detonating and damaging the engine or wasting power. It also enables the use of compression ignition, where the rising pressures inside the cylinder ignite the air/fuel mixture almost instantaneously, all at once.

Petrol engines, in comparison, have to carefully keep their air/fuel ratio much richer, from the stoichiometric level of 14:1, up to 9:1 under some conditions. This is to ensure the fuel doesn’t detonate instead of burning smoothly in a controlled manner. A sparkplug must be used to initiate ignition, with the flame front slowly moving through the mixture versus the instantaneous nature of compression ignition. Gas engines also run at much lower compression ratios – with a maximum of 14:1 seen in practice. Other factors also play a role, but mixture and compression ratio are the primary reasons diesel has such an advantage over gasoline in the efficiency stakes.

Over the years, many manufacturers have attempted to get gasoline engines to operate under compression ignition conditions. While several manufacturers have been able to make this work at low-RPM, low-load conditions. Under harder driving, the higher compression ratios required simply cause the air/fuel mixture to detonate, damaging the engine.

An Incredibly Complex Solution

SPCCI combustion uses a spark plug to ignite a small region of rich fuel/air mix to raise the cylinder pressure high enough to push the rest of the mixture into compression ignition. Illustration: Alex On Autos

Despite the difficulties, Mazda managed to build a production-ready compression-ignition gasoline engine, by the name of Skyactiv-X. Unlike previous attempts, it includes a spark plug in a creative hack that they call Spark Controlled Compression Ignition, or SPCCI, as explained in this excellent video by Alex On Autos.

When running in this mode, the engine runs an incredibly lean air fuel mixture, on the order of 29:1 – so lean, even the engine’s high compression ratio of 16:1 won’t cause the mixture to combust.  When the piston is reaching the top of the compression stroke, a small amount of extra fuel is injected, next to the spark plug. This localized richer mixture is ignited by the spark plug, with the combustion causing an increase of pressure in the cylinder. This added pressure then causes the rest of the mixture to undergo compression ignition. The result is a gasoline engine that can run at a higher compression ratio with a leaner air-fuel mixture than is traditionally possible. The target ratio is so lean that a low-pressure supercharger is used as a pump to supply more air to the combustion chamber.

The SPCCI regime is incredibly efficient, but when high power is required, it makes more sense to run the engine in a typical spark-ignition mode. With a compression ratio of 16:1, however, this would normally be difficult to achieve without detonation. However, modern variable valve timing enables the engine to leave the intake valve open during part of the compression stroke when operating in spark ignition mode. This reduces the engine’s effective compression ratio, allowing it to drop to a point suitable for traditional spark-ignition operation. This allows the engine to smoothly transition between SPCCI and conventional operation, something other manufacturers have thus far failed to achieve.

All this should add up to an engine that makes gains in efficiency, as well as power and torque. Mazda claims a fuel economy improvement of anywhere from 20 to 30% over their previous engines, and 30% more torque. Sadly, the data we’ve seen doesn’t entirely bear this out.

Looking at actual peak figures, the real numbers seem a touch underwhelming. Comparing the 2.0L Skyactiv-X to the previous 2.0L Skyactiv-G, we see a gain of just 12% in peak torque and 14% in peak power. However, this doesn’t take into account performance across the RPM band, and it’s possible that torque gains are much larger in the lower RPM range. As far as fuel economy is concerned, a 3-hour real world test didn’t show a whole lot of difference between the Skyactiv-X and the previous Skyactiv-G. Take into account that the Skyactiv-X also packs a mild hybrid system, and this is fairly disappointing. We’d like to look at this comparison again when the technology is a little more mature, but it’s a concerning result to say the least.

Of course, The sheer complexity of what Mazda has achieved should not be understated. Producing a production-ready, mass produced engine that can smoothly transition between compression ignition modes and regular spark ignition requires the combination of a swathe of technologies, from advanced computer engine controls, to direct injection and variable valve timing. The investment required in research and development to complete such a project is immense; the fact that no other automaker has achieved the feat should indicate the level of difficulty in mastering gasoline compression ignition.

It’s All About Return on Investment

In a direct comparison, the new engine adds significant power and torque, but fuel economy gains haven’t been borne out in real world testing. Image: Whichcar

Despite strong holds on some unique markets like Australia, Mazda remains one of the smaller automakers on the world stage. In vehicles produced, they ranked just 17th in the world, delivering 1.6 million vehicles in 2017. Unlike many other manufacturers, they are not part of a larger consortium, standing largely alone in a field dominated by heavy hitters like Toyota, Fiat-Chrysler, and Nissan-Renault-Mitsubishi. This makes their achievement all the more surprising, given the investment required and the resources available to this David amongst Goliaths.

It raises some eyebrows that Mazda has dedicated so many resources to the ongoing development of the gasoline engine, with many betting on an unstoppable wave of electric vehicles taking over market share in years to come. Other major players like Mercedes have already made moves to end development of gasoline engines. On top of this, with some cities looking to ban fossil fuel vehicles entirely in years to come, one wonders how much Mazda will be able to recoup the development cost over the next decade. Mazda’s own projections state that gasoline engines will still power 85% of all cars in 2035, but the more important figure is the proportion of new sales held by gasoline powered vehicles. BloombergNEF’s modelling expects to see electric cars take a 28% share of new car sales by 2030, so it seems there will still be plenty of time left for Mazda to cash in. It also serves as a useful gap-filler while the company begins a transition towards electric technology.

However, if SPCCI technology is to do well in the marketplace, it will have to make good on its lofty claims. While the new engine certainly packs better power and torque, it hasn’t yet shown a meaningful increase in fuel economy which is supposed to be one of its major benefits. And no matter how new and fancy it is, it can’t compete in the shiny, futuristic stakes with all-electric vehicles. Similar to Mazda’s prior experiments with Miller cycle engines in the 1990s, we suspect this may be more of an interesting blip than a game-changer for the gasoline engine. As always, time will tell.


122 thoughts on “Mazda Investing Big In Advanced Gasoline Tech With Skyactiv-X

    1. Stochiometic mixture is not a constant by volume that’s part of the problem.

      Running very lean of stochiometric means you can lower temps, and burn cleaner even if you require a larger air charge for the same power output.

      A stochiometic burn is actually not desirable in many situations.

      1. That only works for extremely lean. Moderately leaner than stoichiometric means higher temperatures and increased NOx production. I’d be interested in seeing actual comparison numbers.

  1. Also you wouldn’t see many, if any petrol production cars with a compression ratio as high as 14:1. This is normally in the realm of racing engines burning methanol and ethanol fuel.

    1. Toyota vvt-i and vvtl-i engines run 14:1 compression and Mazda skyactiv-g family.
      Millions of cars in tens of capacities run 14:1 compression ratio petrol engines.
      Last time I checked USA and Africa models had tendency to lower compression ratios to cope with shit fuel standards, mitsubishi and Chrysler springs to mind(90’s models in particular)

  2. I’m not sure how this is such a giant achievement – variable valve timing isn’t new, fuel injection isn’t new, notwithstanding the higher compression ratio (which can be as simple as swapping in a different piston) it almost sounds like the whole thing can be done in software.

    1. Yeah but Bolivia still keeps stubbornly rejecting the propped-up coup politician we’re forcing on them, so we might not be able to steal that lithium after all and the pyramid scheme of Tesla might fall over and embarrass everyone.

    1. True. Back then they lost due to underdeveloped infrastructure and battery limitations. The idea was floating around since 1820’s. The first electric car was tested in 1881, in Paris. For a time the electric cars were superior to their steam and ICE counterparts. Now electric cars are still almost the same after almost 140 years. So I believe that in the future it will be easier and cheaper to make biofuels and corresponding ICE or hybrid cars than to make electric cars great again. I like an idea of a hybrid car, where ICE engine burns biofuel at its most efficient RPM/power, which generates electrical energy for powering BLDC (or AC) motors in the wheel hubs…

      1. If you want to go by firsts, then steam cars predate electric cars by Cugnot’s “Fardier à vapeur” (“Steam wagon”) of 1769, and the London Steam Carriage in 1801.

        Meanwhile, the first vehicle with an internal combustion engine was made by François Isaac de Rivaz, a Swiss inventor in 1807. Technically this is not a petrol powered car since it ran on oxygen and hydrogen.

      2. Electric cars work now, charging is solved. Active heat rejection mechanisms allow for high charge and discharge of traction batteries. Car manufacturers are slow to develop this so tesla eat their sandwich. Nissan leaf passive cooling overheats bad. Passive cooling bad. Cobalt chemistries need active cooling.

        1. >charging is solved


          Moderately high charging rates are possible but the rate is still rather low considering the average EV still has a very small battery. The damage it does to the battery is also not solved simply by cooling it, and the infrastructure still cannot handle massive numbers of cars rapid charging daily and there are no technical solutions to that issue except adding intermediate batteries everywhere at a cost of both money and system efficiency.

          1. Of course battery swapping is always thrown out at this point – but with a battery that costs a third of the price of a mid-priced vehicle, or the full price of an economy vehicle, it would be almost easier to swap cars pony express style – and not a bit less ridiculous in practical terms.

          2. Another issue is as the EV ecosystem evolves and charging power demands rise, where does all the electricity comes from? From clean sources or the old nuclear centrals and coal/oil burning centrals? Electrical demand will rise in such a manner that a fleet of electric vehicles will possibly become less clean than a fleet of proper engineered and emission controlled ICE vehicles.
            The advantage for consumers is that consumers will not be the direct polluters but the charging infrastructure will be.
            Clean future will be split by hydrogen ICE or hybrid versions of it. The only issue to solve will be the hydrogen storage/boiloff problems.

          3. Hydrogen is also not a solution in itself to pollution. Producing hydrogen is an energy-intensive process; the overall system efficiency is currently lower than that of battery-electric vehicles. The only real advantage of hydrogen is that refueling is quicker, but in exchange it denies us the freedom of decentralization that we get with EVs. EVs can be charged at home, possibly with electricity from personal solar panels and wind generators; hydrogen keeps us tied to big energy companies and fueling stations.

      3. Kia is shipping electric vehicles right now that are just as refined as their gas vehicles, in fact they share the same platform and are indistinguishable at first glance, but get behind the wheel and step on the gas pedal and see which one is “great”

        1. Kia is not the only one to make electric cars that give a better driving experience than their (virtually identical at first glance) ICE counterparts.
          And I look at the simplicity of the engine/motor in an electric compared to this thing! Crikey, what a nightmare of complexity!

      4. Moryc, I’m not sure where you spent your time the last 10 years or so, but the idea that ‘the ICE is not dead yet’, is pretty much overtaken by reality. Same for the biofuels boondoggle. They were pushed by the agricultural industry to rake in subsidies. We’re already risking the extinction of Orang Utans and many other species thanks to the palm oil plantations, of which half is used to replace only 10% of diesel or so. And palm oil is the best crop, it has by far the highest yield per ha. We simply do not have enough farmland for both food and biofuels.

        “Now electric cars are still almost the same after almost 140 years” -> If you want to say: it still has a battery and electric motor, yeah then you’re right. In reality a Tesla is just as different from a Baker Electric as a Lamborghini is from a Model T. It’s not that development of EV’s has stalled in the past 140 years. On the
        contrary, progress is acceleting. The future is electric, mark my words.

        1. The manufacturing capacities for batteries, and the cost of the materials, and the short lifespan of batteries, dictate high prices for EVs for a long time to come. They have a hard time covering the lower end of the market, plus the second hand market which is actually what 70-80% of the people drive anyways.

          It would take 15-20 years to replace the cars on the roads right now even if all the cars you sold were electric. The actual market share is in the single percentage points and without any revolutionary breakthroughs it will take to 2050 before half the cars sold are electric.

          The internal combustion engine will easily be around to the end of the century, by necessity, especially for work vehicles.

          1. Agreed, in subarctic and arctic climate electric vehicles are a joke in wintertime. Try driving 250km in -30 C without topping up, not going to happen with present tech.

      5. *pets his 2014 Chevy Volt*

        The volt is basically that: ICE that can directly power the electric motors and/or charge the batteries. I get 30-55 miles on pure EV in my volt before engine has to kick over. And it’s crazy how often I’ll be on battery in normal driving. I was recently in the smokies for 2 days and averaged almost 60mpg across the entire 500 mile trip with no grid charging. Just driving around and regenerative braking going nuts on the down grades.

        I love this car.

  3. Someone should tell Mazda. It’s not what and how much goes into these things that matters, (ICE tech already does the job) it’s what comes out that concerns many of us and there’s no mention of that in the article. More efficient pollution is still polution!

    1. I’ve seen this line of reasoning before: “don’t make ICEs better because they aren’t good for the planet. There are two problems with that line of reasoning. First, under the most idealistic projections it will take decades to convert to non ICE based vehicles, so why not help “save the planet” a little in the interim? Second, less optimistic projections point to limited resources for building batteries, toxic end of life pollution (reminiscent of nuclear waste issues that were discounted by supporters), and pollution generated by electricity production in some regions as concerns about the real world outlook for electric vehicles.

      1. Counter points:

        I wouldn’t say don’t make ICEs better, I would say a superior investment is in EV technology.

        ICE is still only an option because nobody has to pay for the pollution they produce. Change that and you’ll have a fast migration in progress.

        The pessimistic projections about resources are merely projections of current technology scaled over time. It does not take into consideration the changes in battery technology which have been significant.

        Lithium battery recycling is just starting up but exists to address pollution and and resource issues.

        Nuclear waste is only a political and engineering problem. We know how to recycle it and if it were an actual problem then it would get addressed in a more timely manner.

        Even coal powered EVs pollute less than the most efficient petrol engines.

        1. > Change that and you’ll have a fast migration in progress.

          Yes. A migration out of the country. It’s an economic suicide, considering that EVs are not good enough to fill all the roles and the performance of ICEs.

        2. actually…. coal powered EV’s DO NOT Pollute less than a petrol engine. Especially if we are talking the no-load cars. When you factor in trucks and vehicles under load and compare that to an ev that’s not doing actual work, that may be true. But coal powered ev’s are definitely not the answer, and even if in some cases they were more efficient, it’s by a slim margin at best and also depends on how you drive the vehicle. Consider the fact that it also takes a base amount of energy to pull the resources, ship them all of the world and manufacture them into a car and you’re missing a large amount of pollution to factor in vs a standard 4 banger. We are talking the kind of pollution that literally destroys ecosystems. People seem to forget that while carbon is an enemy we have to fight right now, it’s BY FAR not the only one, and the types of pollution it takes to create the batteries alone is an atrocity to our ecosystems that may be irreversible. They literally just dump it all and it infiltrates and makes our water supply toxic to the point that no life can exist. But good job gobbling up the propaganda regarding EV’s.

          bonus question: Do they factor in the carbon output whenever they CATCH FIRE?

          didn’t think so.

          But hey, at least you got a shiny new gadget to drive around in?

      2. Firstly, you assumed an awful lot about my personal line of reasoning and my original point still stands… Bad plus or minus Less bad, is still not good.

        Secondly, I don’t recall mentioning EV technology as an alternative. It is flawed thinking to believe that path is better for the planet or ourselves.

        1. Its not flawed at all. EV has 0 emissions this ‘better mazda engine’ does not, period. Investing in an engine which pollutes a little less instead of making one that doesn’t pollute at all is pretty stupid. The fact we also generate a lot of our electricity today with things that pollute are only making it worse. But the reasoning that because we do one bad thing doesn’t mean it’s logical to also have the cars burn fuel for driving as well. Battery tech has caught up, ICE cars are deprecated and we best switch to EV’s asap.

          With enough solar+wind+nuclear we can easily not burn fossil fuels for our electricity as well. Nowadays we literally turn off our wind mills in Belgium and most countries when demand is too low. This is because it’s more economical to shut off the green energy than shutting down the diesel/coal/pellet generators

          And this happens frequently, they even have a term for it ‘curtailment’. It’s totally warped, even when we have the ability to turn off our pollution completely. We decide to just keep burning anyway because its a little cheaper, or rather, a lot of lobbying made it cheaper. If power plants and car owners paid for the damage and pollution they cause we would indeed see a shift a lot faster.

          1. EV has 0 emissions? I would like to see that proven by facts. I find it hard to believe considering the ecologic problems regarding lithium mining and the emissions of power plants.
            Even for solar/wind power the overall sum is interesting: will a typical solar cell in northern climate make a net plus considering the energy or overall economic production costs?
            And regarding the recycling questions: I recommend to wait for the practice test – not in the lab, but in the harsh, dirty reality outside of the lab.

      3. Decades? No, in 5 years already, the ICE is all but dead and sales of new ICE cars will fall of a cliff.

        A new car is expensive and only a small minority can afford the financial risk of buying something that might be worthless in just a few years. Some European countries have already announced the ban of sales of ICE vehicles within 10 or 15 years. People will continue to drive their old clunkers until they can switch to an electric car.

        (Note: Replacing the running fleet will indeed take more time, but your comment was about R&D of new car engines, so my comment only applies to new cars.)

        1. Those are mere political grandstanding. The time frame is long enough that three governments will pass before anyone actually has to make the call, and the next government to be elected will make it a point of NOT banning ICE vehicles like their opponents would, because people still need them.

      4. Take the U.S. our power grid cannot support tens of millions of EV’s on the road. It would have to be totally revamped, more nuclear, NG and coal fired plants to be built to make the DINK Greentopia possible. And since the EV proponents are anti-traditional energy sources well it’s not gonna happen.

        Lets not forget about how nasty lithium mining is and how it pollutes the air and water. Ohh wait since it only happens in the 3rd world who cares. It’s like finding a Ipad user who cares about the slaves who made their toy.

        Then there are the battery waste issues, those EV cars like the Prius are basically throwaway vehicles onces the batteries start failing.

        1. I don’t know about the Prius but I suspect that it is the same as the LEAF, that the battery can be replaced, expensively, but at considerably less cost than the fuel savings over the life of the battery (about 22% of the savings for my usage). The batteries themselves do not go to landfill but retain nominally 50% of design capacity and can be used in power walls where weight is unimportant. A 50% SOH Gen1 LEAF battery might store ~10 kWh of solar, which is sufficient to cover ~ 10 cloudy days of my domestic usage.

          1. These “second life” batteries don’t last long in use. They are difficult to use for things like grid energy storage, because once the battery goes into the final decay, the capacity drop is accelerating with every recharge. They are more valuable as scrap than the trouble of trying to keep the deteriorating cells in balance.

          2. Traction battery on the earlier Prii were about $2500 for a rebuilt pack, newer plugin / EV mode ones may be more.

            If you follow some of the guidance, for example to let sit for at least 12 hours with fully charged battery to equalize every few months you get a lot of mileage out of the packs. Nickel plating the bus bars also seems to help with pack longevity / durability.

            Last I saw some of the 1st gens are still rolling on the factory traction battery with 300,000+ miles.

        2. I can’t speak for the Prius but the battery in the LEAF is replaceable at a cost of approximately 22% of the fuel savings to a comparable gasoline engine over the life of the battery at my usage. The batteries themselves do not go to landfill but can be reused as power walls. A 50% SOH Gen1 LEAF battery might store 10 kWh of solar energy, which is enough to cover 10 cloudy days of my domestic usage.

    2. I assume you also do not drive an electric car. Or a bicycle. Or really anything.

      electric car – Ah yes the green energy of coal power plants saving the earth what a hero I am. At least I’m smart enough to know that the worlds car fleet could never be powered by solar.
      Bicycle – Ah yes truly green energy. Just have to mine some rare earth metals in Africa, ship them off to China for smelting, ship those off to Europe for final assembly, and then get them here in the US. Truly the greenest transportation is one that goes across the globe 6 times via heavy pollutant boats before I even touch it.

      Seeing as we are a child and know that pollution is still pollution and any amount >0 is inhernetly evil we shall invest 0 resources in reducing pollution no we must purge it completely. Welcome to my cult it’s nice here.

      1. The problem with your logic is that you are pointing out /potential/ pollution and not intrinsic pollution as a function of operation. This is to say, EVs do not intrinsically pollute nor is it a function of the manufacture of an EV. Petrol based vehicles however do pollute intrinsically as it is a function of it’s operation. The manufacturing and distribution of both currently pollute but it’s not intrinsic to nature of the operation.

        Also, coal powered EV is still pollutes less than a petrol car. Whoda thunk it.

        1. Internal combustion engines do not intrinsically pollute…. there are other avenues to make fuel for them that fossil fuels. Some you might argue to be carbon neutral or negative even.

          ICEs also do not require nearly the amount of rare earth metals either.

        2. Word games. EV’s simply shift the pollution to the back end where the geeks can’t see it. Just like those who love using China to make their cheap electronic toys with child and slave labor.

          You want the U.S.(and West)to use EV’s? Well pay up trillions to rebuild the power grid, build lots of new power plants to supply baseline energy(which solar and wind cannot).

          Mining lithium is dangerous and fills the air, water and land with poison. Again Geeks don’t care because it happens to a bunch of disposable 3rd world types who only seem to exist to serve a bunch of fake environmentalists.

          Our landfills are full of batteries yet no real solution from the Geeks. Hey out of sight out of mind again eh?

          1. Our landfills are not full of automobile batteries. Nearly 100% of the lead-acid batteries used in ICE cars get recycled. The lithium-ion batteries in EVs have a similarly high rate so far; it’s far less costly to get those materials by recycling than mining.

            There are lots of non-rechargeable batteries in landfills. And some rechargeable batteries (NiCd, NiMh, and lithium) from consumer electronics.

          2. Three contrary arguments:

            1. EVs are more efficient. Most achieve more than 100 MPGe and the most efficient are over 120 MPGe, meaning that they go twice as far on the same amount of energy as even the most efficient hybrid cars and about four times as far as the fleet average. Distribution of electricity is not 100% efficient, but the EV is still well ahead in overall system efficiency.

            2. Emission controls are easier to put in place at a small number of central plants than in millions of tailpipes.

            3. Electricity can be generated from renewable sources: solar, wind, hydro, wave, and so on. As more of the electric grid shifts to renewables the carbon footprint of EVs will drop further.

          3. Wrong on every point.

            I have visited many factories in China. While I would get bored with such a job it is not child or slave labor.

            I can’t speak for the USA power grids but in most countries are designed to handle peak loads around dinner time so the trend is to control BEV charging to occur during the night time lull in demand. A recent technical government survey here in New Zealand shows our power grid will have no problems with the power demands from wide spread BEV usage. Our power currently comes from 84% renewables and we are well on path to make that 100%. Solar has recently become the cheapest form of energy production and something I will add to my house soon.

            Batteries do not go to landfills, they are recycled. Where do you get such bizarre ideas from?

        1. Mine is 7 kilograms of mostly carbon fiber, compared to the lightest car on the market at about 1600kg. You’d have to make bikes out of like solid blocks of milled rare earth metals to compete in the “uses soooo many rare earth metals” competition.

          1. Though unfortunately growing food for human power is then many times less efficient, and takes up more land, water, and fossil fuels, than powering a small scooter for the same job.

    3. Just for the record. Since so many who replied chose to put words and their thoughts into my mouth and mind? Read what I said… I didn’t once mention electric vehicles, in any shape or form and what I did say still applies with whatever technology takes the lead… Bad vs Less bad, is still not good!

    4. Yes, exactly. Efficient pollution will always have a negative payback.

      It’ll also contribute to Mazda becoming uncompetitive, because resources spent on ICE are resources not spent on getting their EV expertise up to speed.

      1. You should read this:

        This mass eutopia of achieving a complete elimination of all ICE and replace everything with batteries thinking its going to solve every problem and even the ones that aren’t problems at all is completely idiotic.

        That being said I think with the recent advancement in batteries a EV is a great alternative and is practical in certain situations and has “zero emissions”. But why can you ignore all the other emission involved? Why can you ignore just how clean a modern ICE is?

  4. The idea is that the more efficient conversion of chemical energy into mechanical energy, the less fuel would be needed to create the same amount of power. Also replacing ICE cars with electric ones won’t save the planet (let’s be honest, Earth deesn’t need saving – it’s humans that are screwed), because we need to make that electric car (process is not very “green”), and make the energy to power it (most of which is made from fossil fuels or from nuclear reactors).

    1. No the idea is to have a vehicle that rarely needs maintenance and can acellerate like a fighter plane, that’s why I want an electric car.

      You can have your smelly gas burning slowpoke clunker that constantly needs oil changes.

      1. I won’t disagree that I like the idea of electric cars, but there is still pollution being created. It’s just not at the car. You still have to charge it, which means you need an electrical power plant of some sort, be it fossil fuel, nuke, or “renewable.” There is also the problem with manufacturing. Whatever type of vehicle we produce, it takes energy to do so. See the statement on power plants. Electric cars==>batteries have a different issue. When producing them, they require noxious chemicals. When disposing, similar issues.
        Bottom line, I don’t disagree that we need cleaner forms of energy and good transportation, but be careful when touting electric vehicles as the end-all and be-all of transportation. They have their own special challenges as well. I consider them to be a stepping stone, just as the current ICE is a stepping stone from the horse…
        But I thoroughly enjoy innovation!

        1. The well-to-wheels pollution of an electric car fully powered by coal is still less than that of a gas car, much less. And that electric car you buy today gets cleaner every day as more renewables come online.

        2. The real kicker is that when charging an EV the energy needs to be produced at that instance. All the while solar farms are idling because they have nowhere to store the energy they could be producing. Thus we build large gas powered motors to drive generators to provide the instantaneous energy.

      2. You must be quite young,.

        First off, plenty of ICE cars fit that bill. They are quiet, very responsive and clean. Most require nothing more than PM if you treat them right for the first 5 years or so, which if the car is under warranty is done by the shop not you. So no worry about getting your dainty hands dirty,

        Acceleration is rather useless in urban and suburban roads. It’s a advert gimmick used to sell 20 something males a car. Seriously if you want to race, rent some time at a track like smart street racers do.

        Secondly oil changes are around 6k miles and very easy to do unless you are one of those men who can’t use basic hand tools and afraid of oil.

    2. It’s not humans that need saving, it’s Earth’s ecosystems. We can improve the manufacturing processes to make them more “green” but it will only happen when we tax for generating pollution.

      Nuclear waste can be recycled, we simply haven’t had an urgent need to complete the technology because of the low amount of waste that is produced. It’s slowly being done but the only rush is a PR issue.

      Also, nuclear reactors don’t have to generate radioactive waste, it’s just that our current reactor types are old and our governments failed to invest in the development better types of reactors in the 1980s. We’re slowly addressing this issue.

      1. Ecosystem will fix itself in a geological age or two. Maybe in few millennia after we all become extinct. Earth will be okay. We won’t….

        Everyone worries about pollution, but only if it happens in their backyard. That’s why in my country they are trying to build single nuclear power plant since 1980’s. Granted, Poland was an eastern block country, but how hard it could be to pick up a safe reactor type, pick a site and start the construction? OTOH last year an underwater sewer pipe in Warsaw broke, causing a major pollution, and they spent millions to fix it. When they reopened the fixed and inspected pipe, it broke again.

        But when it comes to general pollution and “saving the planet”, our entire civilization is doing almost nothing. For example most of the electronic junk that’s made and sold in first world countries ends up in some hellhole where poor people process it with no regard for health, safety and their local ecosystem just to survive. From time to time someone goes there, takes pictures and publish them online, so every ecologically conscious hipster can write about it, share it, or send it to his/hers friends using their newest smartphones, while their last generation devices are on the way to be “recycled” by burning and mixing ashes with toxic chemicals
        And the solution for this particular problem is very simple. Just force companies to recycle their old junk properly, and if they don’t, ban them from selling their new junk. Of course no country will pass such a law, or if they do, they will make it flawed in some way by accident or sheer malice.

  5. Mechanic here in the UK, we have mazda skyactive diesels (and DI petrols) for a while now, perhaps there not common stateside, but they are TERRIBLE. so unreliable. having a honda v-tec like system on the exhaust valves to act as EGR, great idea but implemented so poorly they chew themselves to bits after 30k miles filling the oil with swarf and leaving you with no compression.

    Poor crankcase ventilation so very prone to sludge, resulting in oil starvation.

    Aggressive egr regeneration strategy resulting in oil dilution (and subsequently crank / conrod / turbocharger damage)

    These 3 faults are common and usually result in a complete engine rebuild if not caught early.

    And these engines are not nice to work on.

    Point im going for here is mazda seem to like to pioneer with good ideas and intentions, but they seem to fall short on reliability. Hopefully they get this down, but im not holding my breath.

    1. Glad to see someone address the real issue here: complexity! Higher complexity means higher rates of failure which translates into paying more money. EVs are great because they have a lower total cost of ownership.

    1. This technology is not related in any way to Honda’s CVCC. CVCC is closer in theory to indirect injected diesels, with a separate combustion chamber outside of the cylinder. CVCC also does not rely on compression ignition.

      Skyactiv-X is closer to a traditional direct injected diesel engine plus a sparkplug. There is no separate combusion chamber or additional valving, which is the basis of CVCC technology.

  6. Would it work using ethanol (which has a higher octane)? See, I live in a country that is not so concerned in really substitute internal combustion by electric engines (it’s more a political issue than technological); however, most cars here are “flex fuel”, running on gasoline and/or ethanol made from sugar cane, and gasoline itself is so expensive that almost everyone relies only on ethanol.

    That said: the market would accept internal combustion cars for relatively more years here, giving Mazda more time to recover its money; but Mazda don’t sell cars in Brazil; and if it doesn’t run on ethanol, nobody would buy it anyway.

    1. Certain Mazda engines can certainly cope with ethanol without much issue. Plenty of folks in the US are running their 2016+ Miata’s with E85 (does need the ECU remapped for the different fueling requirements), and I can personally report that it seems to run smoother and with a bump in power. Unfortunately, E85 availability is very spotty here in the states, and actually is much more difficult to find in my area now than just 5-10 years ago. I live in a large major city, and there are only a handful of E85 pumps.

      And pricing here for E85 isn’t too much cheaper than normal gasoline, so with the drop in mpg the cost savings are pretty nil.

    1. one important thing I’ve read elsewhere, the new combustion method in Skyactiv-x only works with lower octane fuel (ron-90).

      Any higher and the engine switches to a normal combustion cycle, and actually loses torque and HP.

      So, it may work with Ethanol, but there’d be no advantage over other cars

  7. Im surprised an EV car is not out yet that has a solar panel built into its roof. Obviously it would be more of a marketing exercise than something that could extend the range of the car to any great extent.
    They could call it a sun roof ……………………… I’m here all week

  8. Well, if the engine makes more torque/power than before with the same fuel consumption, then that means the engine is more fuel efficient. There’s just really not much room for additional thermal efficiency from ICEs. All the low hanging fruits have long been picked so now it’s mostly a few percent here and a few percent there. In that light, 10%+ improvement is pretty good, but really, we’re so close to a wall and thus improvements require some funky tech for any additional gains (like Nissan’s complex variable piston stroke tech). Hybrids have done amazing things when you consider just how heavy modern cars are. That said, the latest ICEs in the Prius are around 40% efficient without this compression ignition tech. Maybe Mazda is just trying to differentiate themselves (as they’ve done in the past), but honestly, they would have likely been better served sticking with a less complicated Atkinson cycle like they’ve done in the past, and mate it to a proper hybrid system.

    1. hybrid systems are expensive and mostly get you the bad of both worlds*, adding a 2nd indirect injector and moving the direct one a bit (and making it smaller) is comparatively very cheap, the rest is ECU magic.
      The whole awesomeness of Skyactiv is that it’s cheap and simple, and yet it rivals far more complex engines in terms of efficiency and power.
      Mazda basically repeated what they did with rotary engines back in the day with Wankel engines – they took a known theoretical concept which the big manufacturers gave up on (SPCCI), and managed to make it work in the real world.

      * non-plugin hybrids rarely any more efficient, most are designed to score well on a lab fuel consumption test. Plugin hybrids have the problem of dragging over 150kg of ICE powertrain when running electric and vice versa. Nobody seems to be successful with a “range-extender” (read: electric car with an ICE generator), because of the co$t.

      1. My chevy volt begs to differ :p I am currently averaging 63mpg with a wide mix of driving and not having to give 2 shits where I can charge on trips (plus long charge times) is the best.

  9. Holly f**k that is complicated and for only 40% efficiency?! I worked for a brushless DC motor startup in the 1990s. Our motor had three moving parts, two bearings and the rotor. It was about 90% efficient and could run for years non-stop with no service.

    I brought a simple Suzuki Jimny, the routine annual service was NZD $400. When I brought my Tesla I asked about routine service, they showed me where to top up the windscreen wiper fluid.

    Sorry, but Japan has lost the plot. After decades of owning Japanese cars I now own an American one and I’m looking at an American motorcycle, a Zero, to replace my Honda.

    1. For whatever reason, the Japanese car industry has been the biggest laggard in EV adoption. Nissan came in early with one of the first mass-produced EVs, the Leaf, but nobody else has followed their lead and even Nissan hasn’t expanded its EV line.

      Part of it is that Toyota, the biggest manufacturer, believes that battery powered EVs are a technological dead end and is instead championing hydrogen. It’s also possible that they’re hoping to slow down EV adoption on purpose to protect their successful hybrid technology, where they are both the market and technology leader. On the other hand, the company’s experience with hybrids mean that they have most of the pieces in place to design a good EV if they ever choose to do so.

      But there is another reason that many of the traditional car makers are reluctant to switch to EV production. That very lack of maintenance that people tout as a benefit makes dealers reluctant to sell them. Here in the US, car dealers currently make very little money selling new cars; the competitive market and the fact that people can easily get dealer cost information on the internet has squeezed out most of the dealer profit. The real money is in service (a reason why car companies are trying to get rid of independent repair shops), and EVs kill a lot of that revenue stream.

      1. Yes, you are right about them not liking losing the income stream from maintenance but at the end of the day consumers will vote with their wallets so they can only hold out so long before they accept that days of expensive regular service charges are going and they need to adapt to a new business model. It will be interesting to watch how that change unfolds.

  10. I bought 2008 Mazda 5 in 2014. It was a two litre diesel and then had 4 years of hell with it. Injections issues, unreliable injection pads and in the end clogging the oil suction almost to a dead stop. Tons of issues with DPF and oil getting thinner because of diesel being put into oil (their idea). So it is hard to believe they mastered anything. Car was great but the engine was plain crap.

  11. I own a Mazda 3 with that engine for little over a year now and it’s been wonderfully uneventful so far. Average measured fuel consumption settled in at about 5.7 l/100km (41.3 us mpg / 49.6 uk mpg) which is a lot better vs the 7.4 l/100km I had on the previous generation Mazda3 (both automatic, the new one having about 65bhp more, vs. The 2.0 skyactiv g 120 petrol engine). We’ll see for long term reliability, but I’m not worried at present. Just had the leisure to see the oil being drained and it was relatively light colored vs. What we usually see on DI petrol lately. I *BELIEVE* that the carbon deposition issues will be lesser than on other DI petrol engines because recirculation happens after the petrol particulate filter which should reduce
    the carbon available for deposition significantly. Time will have
    to tell.

    As to the EV/ICE discussion: not usable in my situation because of a lack of charging infrastructure at home (which I can’t fix / public roadside). Plus while locally emissions free driving is nice, the carbon balance if pretty bad for current generation vehicles. Some manufacturers are working on that so I’m looking forward to what will be on the market by the time I’ll be looking for my next vehicle.

Leave a Reply

Please be kind and respectful to help make the comments section excellent. (Comment Policy)

This site uses Akismet to reduce spam. Learn how your comment data is processed.