compression ratio

American  

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.

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compression ratio British  

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

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Etymology

Origin of compression ratio

First recorded in 1905–10

Example Sentences

Mercedes' rivals have complained to governing body the FIA that the former champions have found a way to circumvent the rules regarding compression ratio.

From BBC

Audi, Honda and Ferrari fear Mercedes have found a way to exploit the way materials expand with heat to have the engines running to a higher compression ratio when the car is on track.

From BBC

Audi, Ferrari and Honda have complained to governing body the FIA because they believe Mercedes have found a loophole in the rule regarding compression ratio.

From BBC

And it's not only on compression ratio, but on other things too.

From BBC

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