Many muscle car engines from the late 1960s and early 1970s benefitted from compression ratios that were as high as 11:1.

Compression ratios were also typically lower ... A: In today’s day and age, the average displacement for car engines is 2.0 liters. That sounds small, but don’t be fooled.

Volkswagen is showing its cleaner side at the International Vienna Motor Symposium by introducing the more efficient EA211 TSI Evo engine ... at a high 12.5:1 compression ratio.