Looks like the "otto" combustion cycle, once developped (still developping ?) by Mercedes Benz

SAAB had a variable compression ratio, gasoline engine that was proposed and prototyped about 20 years ago.

Not true--
An Otto cycle is an idealized thermodynamic cycle that describes the functioning of a typical spark ignition piston engine. It is the thermodynamic cycle most commonly found in automobile engines.

Time, of course, will tell whether this program is a bad one or not. I suspect they've taken a wrong turn in not devoting much more time and engineering in fully electric modes of transport.

So, the charge is still homogeneous? HCCI has been in development for decades. Controlling it has posed great difficulties. Kudos to Mazda for implementing it when possible and harvesting the benefits at least during that mode of operation. Hopefully the map can be expanded over time.

Dan, why the fixation on coal-fired cars?

Lots of countries are now planning gas bans, so I wonder if Mazda is making the right move here?

no matter what kind of old or new tricks anyone uses to keep the fossil fuel industry burning hot or warm AND profitable, nothing beats full electric or other alternative clean energy AND cheap solutions! and for as long as electric charging stations are a rarity, then the best way out would be hybrid ...
now, if this compression thing is really good, fine, then mix it with electric and give us a *hybrid compression combustion electric* engine or whatever the fancy name you're going to put on that PLEASE and then Bob would be your and my uncle! thanks.

Rudolf Christian Karl Diesel would certainly approve of this development. His compression ignition engines ran on peanut oil.

The 'Mallard' of the auto world. The last little improvement before redundancy.