compression ratio

noun

, Automotive.

1. the ratio of the cylinder volume enclosed by the piston at its outermost position to the volume enclosed by it at its innermost position.

compression ratio

noun

1. the ratio of the volume enclosed by the cylinder of an internal-combustion engine at the beginning of the compression stroke to the volume enclosed at the end of it

Word History and Origins

Origin of compression ratio¹

First recorded in 1905–10

Example Sentences

To give it considerably more punch, Mr. Allen applied age-old engine modifications, including increasing the engine’s compression ratio and its displacement.

From New York Times

To achieve this, Nissan said it strengthened in-cylinder gas flow and ignition, which burns a more diluted air-fuel mixture at a high compression ratio.

From Reuters

The fuel system works in synergy with a range of variables, including ignition timing, supercharger boost, compression ratio, clutch application rate and more.

From New York Times

The power bump is thanks in part to a redesigned exhaust manifold and new pistons designed to increase the engine’s compression ratio.

From Fox News

It’s a turbocharged four-cylinder with a variable compression ratio.

From Fox News