How does the Mazda Skyactiv-X engine work?

In our mission to create performance and efficiency without compromise, we developed Skyactiv-X, the world’s first petrol engine with compression ignition. Alongside our Human-Centric Vehicle Architecture, these latest innovations help protect our precious planet and intensify the connection between car and driver.

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[Anarkix]

Bring it to the USA! Seems great coupled with the hybrid system. Would be a great competitor in the fuel efficient crossover segment, I'd buy it!

[lecoureurdesbois]

Skyactiv-G = Gas
Skyactiv-D = Diesel


Skyactiv-X = Mix of the two

[semihgedik]

I hope more car brand will be able to develop this type of engine.

[gpm]

Does it have port injection to keep the valves clean?

[williamgrissom]

This explanation of both gas and diesel engines seems confused, based on my academic knowledge. This came from a Marketing Dept who didn't even talk to the engineers and throws around silly terms they think will impress. The fuel in a diesel engine actually burns slower, indeed only as fast as it sprays into the cylinder. That is designed to last thru about 90 deg crankshaft rotation. That keeps cylinder pressure and temperature more constant as the piston descends, making it closer to the ideal Carnot Cycle. That goal was even stated by Rudolf Diesel in his 1890's patents, per wikipedia article. The liquid droplets burn with a diffusion flame around each one, why a diesel can run much leaner overall O/F and doesn't need to throttle the incoming air (also aids efficiency). The fuel in a normal gas engine is ideally all vaporized and well-mixed with air before the spark occurs. It then combusts fast, as quick as the flame front crosses the cylinder, and during minimal piston motion.

I don't get from the video how the SkyActiv-X is like a diesel, so I'll speculate. I think they first inject a fine spray, which vaporizes and premixes with the air, so that the spark can ignite it. The rest of the fuel is injected later so that it can burn around each droplet as the diffusion flame in a diesel. The premixed cloud igniting raises the cylinder pressure and temperature so that the bulk of the fuel then ignites. But, this would require direct-injection into the cylinder, and they don't depict such an injector in the video. Just found a CNET article which says it does have DI. Going to watch the Engineering Explained youtube about it since he is smart. I'm done with this explanation by English majors.

[veegerman]

On a recent motorway journey to the South West of England, the automatic end of trip display showed 57 mpg. I'm convinced that with a little more of a light right foot, 60 mpg would be possible.
Mazda CX 30 eSkyactiv 2L, 6sp manual.

[-Venu-liki]

We can also use multi sparks in a cylinder either by using sparks plugs or any other methods also increases the speed combustion

[michalz]

When this engine going to be available in the UK?

[armesisp]

Looks like it has a hybrid system with direct and port injection? Is this true? If so i'm gonna buy a Skyactiv X in the future.

[ericb.]

I own a (USA) MAZDA CX 5 GT Reserver 2.5 L. turbo, AWD and love its quality and handling - and almost non-exist tant turbo lag.
NOW to the Skyactive X add: 1.)->Hyundai's Variable Dwell camshaft and 2.)->the newTPS (Transient Plasma Systems) plasma plug for more instantaneous spark control AND color running. The TPS will have to wait a year or two to be market ready.
Still, the gasoline engine may get another reprieve with these technologies.

[AjitV]

I am sorry but I missed it.
Both Conventional Petrol engines and SkyActiv X uses spark plugs to ignite.

So how is the mazda engine different?
The shape of the piston that enables a uniform combustion?

[mrld]

so all you did is more spark and compression like using a MSD?

[mediocre-motorcycle-modifi]

With the lean burn, what sort of after treatment would you need? I imagine you'll get a lot of NOx. Will you have a TWC with a GPF and active SCR?

[kurien]

Is it a GDI engine, or port injection.. so intake valves will be kept cleaner..??

[DemeterVT]

Will there be a Skyactiv-X Wankel Dorito ??

[Manuqtix.Manuqtix]

So hang on. The supercharger is not there to add performance?
It’s there to allow the combustion to happen?

[beachboardfan]

How is this different than high compression superbike engines?

[robertwilliam]

When will this be available in the United States?

[pakjohn]

I'm very late to the party here. What I've wanted know for years is:- What is the etymology of the word "Skyactiv" ?

[tiredhero]

can i have one for my rx7 fc please :)