I know that a Diesel engine has a much higher compression ratio than a gasoline engine.

I also know that Mercedes at least builds Diesels with separate vacuum pumps for the locks and A/C and other stuff, because the engine does not produse the same amount of vacuum as a gas engine.

The question is why? Shouldn't the fact that the Diesel squeezes harder on the upstroke mean that it shound also suck more on the downstroke?

I am not an engineer, obviously, but I would like to know why. Why is there less available vacuum in a Diesel? And if there is a vacuum in a Diesel, why can't it be used?

Does anyone know of a really good Diesel technical website? I have found some, but they are either too simple or too complex.

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Semibodacious Transmogrifications a Specialty

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1985 300D Turbo TD Wagon 219K (Remuda)

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