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 World’s First Production-Ready Variable Compression Engine.Infiniti’s has developed the first variable compression ratio engine which will ever be used in a production vehicle. The compression ratio can vary from a highly boosted 8:1 ratio, to an Atkinson-cycle running 14:1 ratio.
What this means is the engine can produce significant horsepower by using the low compression ratio with a turbocharger, or it can achieve excellent fuel economy by using a high compression ratio and an efficient engine cycle.
Now there aren’t simply to modes the engine runs in, it can vary and run at any compression ratio between 8:1 and 14:1, allowing for optimal performance and efficiency for whatever the driving condition may be.//Engineering Explained