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

The compression ratio of this engine was lowered by almost 20 percent from that of the vertical 4.

From Project Gutenberg

This seems low, considering the compression ratio and probable leakage past their rather weak piston rings, but it is possible.

From Project Gutenberg

It is significant that in 1930 the Packard diesel had a compression ratio of 16:1, whereas in 1931 it has been reduced to 14:1.

From Project Gutenberg

Any desired ideal efficiency may be obtained from any of the cycles by selecting a suitable compression ratio.

From Project Gutenberg

You've got thirty tons of fuel—you want to find the compression ratio of the number-one firing-tube chamber—so what do you do?

From Project Gutenberg