As Mazda continues the current rollout of its still-new Skyactiv technology, the automaker is already looking at improving its family of engines for even better fuel economy and emissions reductions. Automotive News reports that with stricter fuel economy and emissions regulations planned for 2020 and 2025 in Europe, Mazda will likely release engines with next-generation Skyactiv 2 technology by the end of this decade, and Skyactiv 3 units just five years later.

The latter is expected to focus on improved engine cooling and lessening energy losses, but the big news in AN's report is that the next-gen Skyactiv 2 engines will use Homogeneous Charge Compression Ignition, or HCCI. This type of ignition is very similar to how a diesel engine operates (with high compression and using the compression stroke for fuel combustion rather than spark plugs), a method said to provide a cleaner and more efficient fuel burn – to the tune of a 30-percent improvement in fuel economy compared to current Skyactiv engines. Other automakers, including Hyundai, have already announced they are developing HCCI powerplants with similar technology and characteristics, so Mazda likely won't be a lone wolf here.

Equipped with HCCI technology, Mazda figures to be able to compete with larger automakers in terms of fuel economy and emissions without resorting to hybrid powertrains, continuously variable transmissions or automatics relying on more forward gears (eight or more) for optimal efficiency. Some of the challenges of HCCI, according to AN, include the need for better engine cooling, risk of misfire at high and low rpm and uneven engine performance based on fuel properties.


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  • 37 Comments
      • 11 Months Ago
      [blocked]
        Cory Stansbury
        • 11 Months Ago
        Everyone has worked on HCCI at some point it seems. They all make the same claims, the same projections, and then you never hear about it again. Same with camless engines.
        icemilkcoffee
        • 11 Months Ago
        None other than Autoblog drove a GM HCCI prototype and reported on it back in 2009. GM does deserve credit for being a pioneer. As always, timing is never the general's strong suit.
          • 11 Months Ago
          @icemilkcoffee
          [blocked]
          chanonissan
          • 11 Months Ago
          @icemilkcoffee
          really, benz have the diesotto out before GM, honda have a prototype before gm, and nissan have a prototype before GM, i will give you my source now. http://www.greencarcongress.com/2008/08/nissan-provides.html (which is nissan second an official prototype) (nissan first prototype in 2003 was a 2 cylinder engine). http://www.greencarcongress.com/2005/10/honda_making_si.html http://www.popularmechanics.com/cars/news/4220723
      plarson79
      • 11 Months Ago
      Well, Mazda found a way for gas engines to run at 13:1 without using Premium Fuel and they announced that back in 2009 with a ,any saying it can't be done. No reason to think in 2020 (only 6 years from now) they can accomplish this feat. Time will tell. I hope they can find a way.
        chanonissan
        • 11 Months Ago
        @plarson79
        actual 14:1, they have that engine in japan from 2009, so it was done before 2009.
          kal_elkal
          • 11 Months Ago
          @chanonissan
          It's only 14:1 in markets that don't use 87 Octane fuel like here in the U.S. In markets where "Premium" fuel is standard, it's 14:1. In markets that use "Standard" fuel, like here in the U.S., it's 13:1.
        2 wheeled menace
        • 11 Months Ago
        @plarson79
        Sure, there are all kinds of tricks up their sleeve that they have been waiting on. Federal CAFE regulations are forcing their hand. It is a shame that they didn't develop this stuff earlier. It would have been a huge competitive advantage for the company. The secret sauce here for the skyactive motor is that it's an atkinson cycle engine with direct injection.
          plarson79
          • 11 Months Ago
          @2 wheeled menace
          It's not an Atkinson cycle engine. Just uses various properties of the cycle.
          2 wheeled menace
          • 11 Months Ago
          @2 wheeled menace
          I've heard that it was an atkinson cycle engine from many news reports. Maybe they are wrong.
          chanonissan
          • 11 Months Ago
          @2 wheeled menace
          I am glad to see mazda is still research HCCI but i think they are far advance than what they are claiming. If nissan have this abstract from 2003 how comes they are just realize the ratio is 18:1? Any way gas is not very easy to control, because it is lighter, nissan would have this engine from 2003 with their abstact they presented or benz would have this on the market being first with the diesotto, in 2007 which was the most stable at the time. Any one interested in HCCi tech here is some info http://books.google.ca/books?id=zISCpIrKD8QC&pg=PA77&lpg=PA77&dq=nissan+hcci+engine&source=bl&ots=s5gU604IYi&sig=0ju9Hi4BZVtkINEFHvvH90xR4zE&hl=en&sa=X&ei=1bXNUtSLLOWL2AW_4YH4CA&ved=0CIcBEOgBMAk4Cg#v=onepage&q=nissan%20hcci%20engine&f=false
          AcidTonic
          • 11 Months Ago
          @2 wheeled menace
          No it uses a special exhaust manifold that keeps cylinders 1 and 3 separate from 2 and 4. It keeps the pressure waves from the other cylinders from pushing against the outgoing stream on the opposite bank. Basically twin-scroll technology which is used in turbo cars to spool them up faster but without a turbo. That and variable cam technology which lets them change the amount of cylinder pressure easier so they can run higher static compression then adjust the dynamic compression via cam timing. Google the skyactive exhaust pictures to see what I mean.
      _I_I_II_I_I_
      • 11 Months Ago
      Mazda is the new Honda.
        mcc1975
        • 11 Months Ago
        @_I_I_II_I_I_
        You are completely right. Can't think of a new Mazda that's not fantastic inside and out...
      CEC
      • 11 Months Ago
      I really like the current skyactive, I hope the next generation takes tech even further.
      danwat1234
      • 4 Months Ago

      I wonder when HCCI will actually happen, if ever. Maybe on the fly Atkinson cycle for all cars, not just hybrids, is a good solution for now. Is Honda doing that for the 2015 Civic?

      Hopefully the diesel cars in the USA will become available with sizes smaller than 2 liters, because 2 liters gets around 40MPG real world average. Calculating the additional energy that diesel has per volume than gas, it's not really more efficient than a modern gas car.
      A 1.4 L diesel car might be able to get MPG close to a Prius, but then why not get a Prius..

      jebibudala
      • 11 Months Ago
      This is really an older technology. The issue hasn't been getting amazing MPG's. It's always been the strict emissions requirements from the byproducts emitting from the tailpipe. Why do you think lean-burn engines mysteriously went away? Sometimes I wonder if our EPA and government is secretly in bed with the oil companies.
      Tom Janowski
      • 11 Months Ago
      Thank you Mazda for leading the way with the traditional engines and transmissions :)
      James B
      • 11 Months Ago
      I was under the impression automakers have been evolving diesels to lower peak cylinder pressure allowing more prolific use of aluminum blocks. Excited to see how they are working around this.
        Aaron
        • 11 Months Ago
        @James B
        Mazda has a SkyActive-D engine that uses lower-than-typical Diesel compression ratios, too. The SkyActive-G (gas) engine uses higher-than-typical gas compression ratios.
      Tweaker
      • 11 Months Ago
      Now that we have today's news of yet another delay for the diesel amid reports of problems in Australia and UK, much of the confidence expressed below is misguided. Under the surface, there seems to be trouble. Mazda needs another motor, their diesel gambit is failing and reports are coming in about rust problems in the 3. T
      Kurt
      • 11 Months Ago
      Good news! No more spark plugs and coils, but considering the added expense of replacement high pressure injector, special sensors, and ... I don't want it. Even if they are designed to last the life of the vehicle, prices will be astronomical, unless they decide to use 1 or 2-cylinder engines.
        danwat1234
        • 11 Months Ago
        @Kurt
        It'll be part time HCCI, it'll still have spark plugs for certain modes
      Pandabear
      • 11 Months Ago
      If they managed to do Urea injection it would solve the NOX issue.
      wric01
      • 11 Months Ago
      Rumors at best, if anything why would mazda license the same hybrid technology as prius to produce their mazda 3 hybrid. So hybrid is mainstream skyactive 2 is experimental it is still researching/developing.
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