Five insights into Mazda’s revolutionary gasoline engine – plus one about Mazda’s most famous engine technology ever!
Mine Proving Ground, Yamaguchi Prefecture, JAPAN –
1. It’s a super lean machine
One key to efficiency is burning more air with less fuel mixed in (‘lean’ as it’s known) and it’s what modern, downsized turbo engines have been doing for some time now. The X engine can, thanks to compression ignition, operate at an even leaner ratio.

2. It’s totally new
The engine it a totally new development and shares almost none of its parts with the current Skyactiv G or D engine families.
 

3. It works better on cheaper fuel

Or at least, fuel with a lower RON (octane rating). Since it uses compression ignition, lower RON is actually better for Skyactiv X.
“We found that 91RON fuel gives better low end torque, and higher RON means it’s harder for compression ignition to occur,” says Mr Hiroshi Tokushige, Mazda’s deputy general manager of powertrain development. Given lower RON fuel tends to be cheaper in Singapore, that’s good news for future Skyactiv X owners.
That chunky silver bit sticking out in the front is the supercharger unit
4. It’s supercharged
Technically speaking, the Skyactiv X engine is a forced induction unit. It has a mechanical supercharger, but this is not for the conventional use of cramming in more fuel/air to make more power. “The purpose is to increase the amount of air taken in for lean combustion, it’s slightly different from conventional system,” says Mr Tokushige.

5. There will be smaller capacity versions
While the engine is currently a 2.0-litre, Mazda is currently considering smaller displacements. “To support our portfolio, we have to have another displacement, it is not the target yet but we will have several displacements,” says Hidetoshi Kudo, Mazda’s executive officer in charge of research and development.
 

6. Rotary forever!
This isn’t actually about Skyactiv X, but Mazda fans will undoubtedly be happy to learn that the company hasn’t abandoned its signature engine technology either. “Rotary development is still continuing,” says Mr Kudo, with a smile.
To find out why that’s a big deal, just listen to the wonderful hair-standing cacophony that it Mazda’s LeMans winning 787B prototype racer below.