[IgorPartola]

So how exactly does this work? And why is it more effective and how does it allow you to run super lean while producing the same amount of power? Also, presumably running lean would mean lower emissions, but is that really true?

[philipkglass]

Running lean, highly compressed, and highly efficient reduces expected production of carbon monoxide and residual hydrocarbons. But it significantly increases nitrogen oxide formation, as in diesel engines. So I wonder how the emissions control system deals with the extra NOx -- that has (see Dieselgate and continuing related fallout) proven quite a sticky problem for high efficiency diesel engines in passenger vehicles. The cheap "solutions" were mostly cheats and the actual solutions cost more.