We want to do that because we have too many variables here. We've already got dV p we'll get rid of p as an additional variable and replace it with V which is already in here.

我们之所以要那么做,是因为这儿有太多变量了,我们已经有了dV，我们要把,作为额外的变量消去，用已存在的V代换它。

麻省理工公开课 - 热力学与动力学课程节选

For the Ford F-150, the most popular vehicle on American roads, they take out the inevitable V-8, and replace it with a four-cylinder engine, an average of 22-kilowatt-hour battery packs, and two 60-kilowatt electric motors.

FORBES: Written by Jim Motavalli