Compression ratio

Compression ratio is a measure of the change in volume of a combustion chamber in an internal combustion engine across the combustion cycle. The ratio is measured as maximum volume divided by minimum volume. A higher ratio leads to more energy efficiency. However, in a gasoline engine, it also increases the tendency to knock, requiring higher octane gasoline.

The Refinery Reference Desk includes content derived from our industry experts as well as from public data sources such as company websites. Nothing herein is intended to serve as investment advice. This material is based on information that we believe to be reliable and adequately comprehensive, but we do not represent that such information is in all respects accurate or complete. McKinsey Energy Insights does not accept any liability for any losses resulting from use of the content.

McKinsey uses cookies to improve site functionality, provide you with a better browsing experience, and to enable our partners to advertise to you. Detailed information on the use of cookies on this Site, and how you can decline them, is provided in our cookie policy. By using this Site or clicking on "OK", you consent to the use of cookies.