by Daniel DeGasperi

Mazda is readying a breed of lighter and higher-revving diesel engines to power future sports models, including the next Mazda3 and MX-5.

Speaking at the launch of the all-new Mazda6, Mazda Motor Corporation program manager Hiroshi Kajiyama confirmed that the company is committed making diesel engines work in sporting applications.

“I want to focus on diesel for sports car,” Kajiyama-san said. “We need to challenge [conventions].”

Perhaps surprisingly, the program chief nodded approvingly at the suggestion next Mazda MX-5 could utilise a turbo diesel engine. “Ah [but] not only MX-5,” he interjected, without being drawn into further speculation that the planned next-generation RX-7 could utilise a compression ignition engine.

Mazda’s Skyactiv-D 2.2-litre turbo diesel, as seen in CX-5 and Mazda6, has both a high 5200rpm redline, and what the company claims to be the world’s lowest compression ratio, at 14:1. Asked whether Mazda is working on a diesel engine that revs even harder than the current Skyactiv-D, Kajiyama-san responded: “Yes, of course [it can get] lighter and higher revving.”

Currently, most diesel engines require a strong, heavy iron cylinder block to ensure their longevity, however lowering the compression ratio has enabled Mazda to use an alloy block for the Skyactiv-D. Stronger internals is typically what makes diesel engines heavier than their petrol equivalents, and in front-engine applications, it adds more weight over the nose, which affects handling.

The program chief explained that the company is working on reducing the compression ratio even further to enable engineers to use even lighter materials.

“The key point is the compression ratio … because our compression ratio is the lowest. That is the key for weight.”

Reinforcing the point that Mazda is continuously improving its current diesel range, Kajiyama-san pointed to the small differences between the CX-5 and Mazda6 diesels, both of which seemingly use identical 2.2-litre Skyactiv-D engines.

“What is the difference between Mazda CX-5 diesel and Mazda6 diesel? Engine noise is a big difference. Mazda6 is quieter. It is an improvement item, better insulation, and completely changed engine management system.”

The next-generation Mazda3, due late next year, will be built on the same platform as the CX-5 and Mazda6. Asked whether the 3 will adopt the 420Nm 2.2-litre turbo-diesel from those models, Kajyama-san gave a conceited nod, admitting that “any engine can be shared [across the three models]”.

That would mean a larger, perhaps lighter, Skyactiv-equipped Mazda3 could top the Golf Mk7 diesel for performance and economy, at least until a Golf GTD replacement is prepared.

Hiroshi Kajiyama isn’t fond of the downsizing-plus-turbo trend with petrol engines, saying that “I don’t like that strategy … I think the engine sound is very poor with smaller engine. Customer cannot get linear feeling … I think Mazda customers want a linear [throttle].”

The belief that a diesel engine can work in a sports car is more commonly shared, though on a small scale. However, Kajiyama-san believes that increased popularity of diesel in passenger cars will eventually flow to the sports car market when improvements to revability and engine refinement are made.

“Every customer can understand diesel merit,” Kajiyama-san said. “In the case of Japan, our diesel mix for CX-5 is over 80 per cent, and also Mazda6. So I think diesel [perception] is changing for market, so maybe Australia too…”

  • Sydlocal

    Maybe that changed engine management system of the Mazda6 diesel means it won’t have as many problems as the CX5 when it comes to oil dilution? Highly doubt it though.
    As long as it has a DPF and people drive short city distances, there will always be problems with oil dilution…

  • Noddy_of_Toyland

    Not very forward thinking from Mazda, to be investing further into dirty diesel cars. I am a diesel fitter by trade so I love the engines, but I still don’t think they have a place in Japanese sports cars.

    • Popper

      But that’s what Mazda is all about. Mazda don’t simply follow the herd. They may come up with something that changes your view on the subject of diesel engines. Then you will wonder why you ever said what you said above.

    • Sturmgewehr

      its my understanding you can refine bio diesel fuel from corn, or something. a diesel that can also run on organic diesel fuels a more feasible alternative energy than EV’s at this stage. plus home grown bio diesel eliminates the dependency of middle eastern/arab oil

      • Noddy_of_Toyland

        You’ll get no argument from me about bio diesel being a cleaner and more sustainable fuel, but with the government happy to profit off imported Arab oil and selling natural gas, why would they want to mess that up by investing more in biodiesel? And Popper, a fat slug of torque at 1500rpm is lovely, in a wagon or ute. But I like being able to work an MX-5 for its power, utilising the lovely gearshift to make the most of the small power, and wringing its neck to redline. The last diesel sportscar I drove (a TT) redlined at about 5000 I think. So not for me.  

        • Oilsforspoils

          Modern diesels mated to fast-shifting dual clutch style transmissions can make the best of the lower tacho range and keep the mill in the fat of the torque. The biggest problem has been turbo lag. Bi or twin turbos need to be thrown in the mix before we will get the responsiveness to be classed as a sports car engine.
          Despite all this – I say bring it Mazda. Stick it in the 3. I am ready to purchase my first ever Mazda, just make it happen :)

  • Popper

    “I don’t like that strategy … I think the engine sound is very poor with smaller engine. Customer cannot get linear feeling … I think Mazda customers want a linear [throttle].”
    I agree entirely.

    And I also want reliability.

    All in all, with Mazda you’re in safe(er) hands. That’s why we have one :)

  • K20A

    Another prove that Mazda is one of the most progressive, forward thinking Japanese automaker at the moment.

    Nice to see that they put effort making cars for driving enthusiasts.. skyactiv, gram strategy, and now they show they care about how the engine sounds and throttle feels.. Impressive.

    • Zaccy16

      exactly something that toyota (excluding the 86) don’t give one little thought about, making it fun to drive!

    • Drive

       Personally I don’t care how they sound outside, so long as they aren’t noisy inside.

  • RealZoom

    I find it funny to read all these comments about Mazda’s forward thinking, when only 2 years ago their most advanced engine (in a mass production vehicle) was effectively the same one they’d been making 15 years earlier.

    They are only now building engines with Direct Injection despite other car companies utilising the technology for nearly a decade.

    And to bag small capacity turbo engines for their sound, and then go on to say they want to build diesel sport cars….. I have a diesel sports car, and while the torque etc. is awesome, the sound is awful compared to any petrol powered sports car. Furthermore, diesel sports cars aren’t exactly new or forward thinking…. all the euro brands have been building them for ages!!

    Mazda have still yet to release a car with a modern automatic gearbox either….

    • Sydlocal

       Give me Mazda’s new 6 speed auto over a “modern automatic” DSG/CVT any day if I wasn’t allowed to have a manual. Especially on something I would plan to keep for the long term. In fact, anything recent from ZF etc would suffice over a DSG/CVT. Anyhow, CVTs are hardly what you would call modern and have been around for decades in one form or another.

      Plus how is their new auto transmission not modern? How many other torque converter autos lock up 95% of the time in every gear? What is wrong with taking something well proven and making it even better? Especially when you are such a small company with a very limited amount of money to spend on R&D. Even VW are still using that theory with the 1.2t which is still an old SOHC 8V engine, which is even older than the “ancient” Mazda engines you were talking about. Speaking of Mazda engines, did you happen to forget the MZR DISI turbo engine fitted to the mass produced 6/3MPS and CX7? When released (a little over 6 years ago) it was one of the first turbocharged, direct injected engines in the world behind IIRC a couple of VAG models, who have considerably more $$$ to spend on R&D. 

      Having said all that I did think it was funny that they were baging out small capacity turbos then said they want to build a diesel engined sports car. Then on top of that they said they wanted to have cars with a linear throttle as well as a diesel powered sports car. No turbo diesel, or anything with a turbo for that manner, has a truely linear throttle response. Strange and hypocritical….

      • RealZoom

        I’m not saying Mazda hasn’t done well with what they have, but if their program manager truly sees them as being ahead of the game with diesel sports cars and other technologies, then he’s either been smoking way too much crack, or has never stepped outside of Japan.
        And I really don’t understand the hate people have towards DSG and CVT gearboxes. I used to own an Audi with a DSG, and it was the best gearbox I’ve ever driven with! I now have a slush box with a fancy lock up torque converter from BMW, and I hate it!! I thought I’d get used to it, but after a year, the cars now for sale.

        And totally agree about the throttle response etc. very hypocritical.

      • Zaccy16

        exactly, the new skyactiv drive is as advanced as any dct or cvt!

    • Drive

       Mazda still dragging the chain with 10,000KM service intervals. Living in the 90s!

      • Sydlocal

         Along with most other Japanese manufacturers…

        • Drive

           Camry and Aurion are 15,000 Km.

          • Sydlocal

            Hence use of the word “most”!
            Just so all the facts are out, yes the Australian manufactured Toyotas are 15,000km, but the time period is 9 months. So neither here nor there!

            Also the rest of Toyota’s passenger range is the same as MOST other Japanese manufacturers with 6/10,000.


  • Dave S

    A diesel in a sports car. A sports car is one parts sounds and 1 part performance. never heard a diesel sound sports, who wants black soot pooriing out of their small sports cars – not a good sign.

    Free reving sports car and ‘sounds like a tractor’ does not go together.

    Just say no to this one mazda,

    • Drive

      You probably don’t know what it’s like to drive a high-powered diesel car. It’s more like driving a big 6 or even an 8 cylinder petrol with the buckets of torque that give them a massive shove.