Knowledge Session no.60 Variable compression ratio Engine Variable compression ratio is a technology to adjust the compression ratio of an internal combustion engine while the engine is in operation. This is done to increase fuel efficiency while under varying loads. The 2019 Infiniti QX 50 is the first commercially available car that uses a variable compression ratio engine. Variable compression engines allow the volume above the piston at top dead centre to be changed. Higher loads require low

How GM's Variable Compression Engine Works | Engineering Explained