Every car engine has quite a few details, ranging from cylinder count to compression ratios. How does changing the compression ratio affect the engine?

Nissan’s variable-compression turbo (VC-Turbo) is a unique engine capable of variable compression adjustment. Unlike traditional engines, which have a fixed compression ratio, the VC-Turbo engine ...

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?