Compression ratio is also what makes engines like Mazda's Skyactiv-G engine so efficient. The first of a wave of new high-compression and variable-compression engines from Mazda, ...

Racing engines tend to be very high compression, with NASCAR engines, for example, having a compression ratio of 12:1. High compression is also more efficient, so it would seem reasonable to ask ...

The static compression ratio (sometimes called the mechanical compression ratio) is a handy reference that engine builders use to build and describe engines, but no two engines with the same CR ...

The Skyactiv-X engine has been designed to have a very high compression ratio—16:1 in fact—and to use a very lean air:fuel ratio, but both of these are just below the threshold needed for HCCI ...

Increasing an engine’s compression ratio is a proven way of unlocking extra horsepower, but there’s a point of diminishing returns. The team at Garage 54, the Russian mechanics who built a V16 ...

These engines require such a high compression ratio because diesel fuel is less volatile than gasoline, so it's harder to ignite under the same conditions. This is where the piston shape kicks in.