by Alex Gibson

Mazda will launch its second generation of Skyactiv engines by the 2020, with a view to improving fuel economy by 30 per cent.

The ‘Skyactiv 2’ engine range, as it will be known, is set to supersede Mazda’s current line-up of Skyactiv engines, even though the Japanese car maker is still rolling its full range out.

The second-generation engines will focus on improving internal combustion to reduce fuel consumption rates, and will also be made compliant with strict European emissions regulations, which will require engines to emit 95g/km of CO2 or less by 2020, and 65g/km CO2 or less by 2025.


“If we want to dramatically improve fuel economy from here, the only route is through lean burning,” Mazda executive officer for powertrain development Mitsuo Hitomi told industry journal Automotive News.

“The next step is the 2020 European regulations. It [Skyactiv 2] must help us with that.”

Hitomi also indicated the 2025 regulations may require development of a third generation of Skyactiv engines.


Hitomi’s comments means Mazda’s current range of Skyactiv engines will be less than a decade old when they are superseded. First seen in 2011 with the facelifted second-generation Mazda 3 (pictured above), Mazda’s Skyactiv range uses a high compression ratio of 14:1 to help reduce fuel consumption. The Skyactiv 2 range would seek to use a compression ratio closer to 18:1 to achieve Mazda’s goals.

It will also use homogenous charge compression ignition (HCCI) to reduce nitrogen oxide emissions, and improve fuel economy.

One challenge for Mazda will be management of the HCCI technology; engineers will need to manage the number of revolutions in the engine, as too many would cause the risk of a misfire, while too few would result in too-low temperatures for effective operation.

Hitomi also said the focus on compression ratios means Mazda can forego development of a new transmission, as the current range’s six-speed automatic will be satisfactory when paired with Skyactiv 2 engines.

  • Phil

    Mazda’s experience with Miller cycle engines will probably help them here, though given the narrow rev range HCCI engines like to operate in, a rethink on the transmission would be advisable. Given the high static compression it seems like they’re aiming for a pure HCCI engine, and not a hybrid design such as VW and GM have been working on.

  • DanR

    Ideally ide like to see Mazda go down the tiny turbo route to give their engines a bit more torque in the low end. Having said that, its hard to argue with the reliability of their current (petrol) engine range.

    • suomi95

      Glad you prefaced that with petrol! The diesels certainly haven’t been crash hot.

      • Sydlocal

        Did a Mazda diesel kill your first born or something? Because you never miss an opportunity to stick the boot in.
        Again, there is nothing wrong with the engine itself, it is the DPF and the post injection burn cycle used (the same concept used by almost every other brand). It is not just isolated to Mazda, with other brands like Subaru/BMW/VW/Honda etc also having excessive oil dilution problems caused by the post injection DPF burn system. To the point that Honda in the UK had a recall due to the oil dilution being so bad that they had cases of engine runaway! That is even worse than the reported CX5 cases of excessive oil dilution.
        DPF and its issues aside, (which is causing issues with modern diesels REGARDLESS of brand) the Skyactiv-D is one of the best modern diesels out there to drive and I have driven a few. I have yet to drive a diesel that revs so cleanly (you could nearly even call it enthusiastically) up high in the rpm range and not ‘fall off the cliff’ so drastically above 3,500-4,000rpm. It is a great engine ruined by a flawed system used to remove particulate matter. Just like most of the other recent diesels out there.

  • m80

    18:1 compression ratio is impressive for a production engine. Clever how it is achieved.
    Maybe they could spend this much time on a rotary for a new RX7. Wishful thinking most likely

  • Zaccy16

    Sounds like great tech for low emissions mixed with mazdas trademark driver enjoyment! also these skyactiv engines also have proven real world economy as well not just claims!