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 ...

We might be covering ground that's well trampled for many, but the static compression ratio of an engine is simple to understand: it's all the volume of a cylinder above the compression ring at Bottom ...

Over the course of a round-table discussion and a separate private interview with Alain Raposo, Alliance global vice-president, powertrain and EV engineering and Shinichi Kiga, chief powertrain ...

It seems like every major automaker these days is using tricks like variable-valve timing – often in conjunction with forced induction – to eke better efficiency out of their engines while still ...

While the fashion in high-tech automotive developments might lean towards hybrids and electric vehicles at the moment, there’s still plenty of scope to improve the good old internal combustion engine ...

A French company may be on its way to a mass-produced Variable-Compression-Ratio (VCR) engine block that reduces fuel consumption by 30%. The French company MCE-5 Development claims its MCE-5 VCR ...

You've heard the term compression ratio before, but have you ever wondered exactly what it means? Well, it's time to explain exactly what compression ratio is, and why every carmaker is now obsessed ...

Something I've been kicking around for a while, and wanted to get opinions on: Is there a reason we can't use variable intake valve timing to "optimize" engine operation for E85 operation, while still ...

Strictly defined, compression ratio is the total volume above the piston at bottom dead center (BDC), divided by the total volume above the piston at top dead center (TDC). First, let's look at the ...