Compression ratios usually vary between 1.05–7 per stage; however, a ratio of 3.5–4.0 per stage is considered maximum for most process operations. Quite often, the temperature rise of the gas during the compression dictates a limit for the safe or reasonable pressure rise.

Is higher compression ratio better?

A higher compression ratio (CR) is beneficial for engines. That's because the higher ratio allows for an engine to extract more energy from the combustion process due to better thermal efficiency. Higher compression ratios allow the same combustion temperatures to be achieved with less fuel.

What happens if compression ratio is too high?

Higher octane means the fuel can resist self-ignition at a higher pressure and temperature than a fuel with a lower octane rating. All things equal, engines with higher compression ratios require higher fuel octane. ... For this reason, running a higher compression can cause engine damage, but that's gradually changing.