Ideally, an ethanol engine needs a compression ratio of 19:1 instead of the 10:1 typical of petrol engines.

理想情况下，乙醇发动机需要的压缩比是19：1，而不是典型汽油引擎的10：1。

youdao

In a diesel engine, there is no spark plug. Instead, diesel fuel is injected into the cylinder, and the heat and pressure of the compression stroke cause the fuel to ignite.

柴油发动机内没有火花塞，取而代之的是将柴油喷入发动机气缸，然后压缩冲程在高温高压下引起燃料点火。

youdao

However, when the same static pages are delivered from a Servlet engine dynamically, caching does not occur and, hence, compression was possible.

不过，当相同的静态页面从Servlet引擎动态发布时，不会发生缓存，因此可以进行压缩。

youdao

Its Variable Compression Engine can alter its compression ratio (the volume in a cylinder when the piston is up compared with the volume when it is down) from 14-1 to 8-1, depending on the circumstances.

ECONOMIST: Fuel economy

In the Scuderi engine, the four strokes are divided between two paired cylinders a small one handling intake and compression and the other handling combustion and exhaust.

FORBES: How To Get 50 MPG Out Of Your Gasoline Engine