You might have heard about high compression ratios, but what exactly are they, and what kind of effect do they have on an engine's fuel efficiency?

A gasoline piston engine that can dynamically change its compression ratio —that is, the amount by which the piston squeezes the fuel-air mixture in the cylinder—has long been a holy grail of engine ...

Apart from the very curious, not many people ask why diesel engines, compared to gasoline, run higher compression ratios. The argument is reasonably straightforward and starts with fuel ...

Low- And High-Compression Fuel Economy Engines: The Techniques Are About The Same, But The Approach To Each Is Somewhat Different. A.Most stock cylinder heads have factory-cut undercuts of the type ...