Mazda Skyactiv-X: experiments with a diesel cycle on gasoline

After last year, Japanese engineers announced the imminent introduction of an innovative gasoline engine on the conveyor, there is still debate: will the new Skyactiv-X unit give fuel economy in comparison to the traditional Mazda's Skyactiv-G line?

And now restyling came to the test, and our British colleagues from the magazine Autocar on this occasion talked with leading engineer Mazda Aisha Nakai.

Recall that in the Skyactiv-X project, the Japanese decided to implement a cycle with the ignition of a homogeneous mixture of compression HCCI (Homogenous Charge Compression Ignition), a kind of diesel cycle on gasoline. In the series, no one built such an assembly, although there were many experiments in the industry. In its pure form HCCI did not work, but its variation was invented: Spark Controlled Compression Ignition (SCCI), that is compression ignition with control by candles. By the way, without the spark plugs in engines like HCCI, at least on some modes of operation, the predecessors of Mazda engineers did not do the same. The two-liter gasoline unit Skyactiv-X has a compression ratio of 15: 1, which is quite a lot, since the engine is not atmospheric, but is equipped with a drive supercharger.