What would be the compression ratio for small engines?

The compression ratio for small engines typically ranges from about 8:1 to 12:1, depending on the engine design and intended use. Higher compression ratiOS generally lead to better efficiency and power output, but they also require higher-octane fuel to avoid knocking. Small engines, such as those found in lawnmowers or small generators, may have lower compression ratiOS to accommodate lower fuel quality and operational demands.