It has nothing to do with compression ratio actually. The amount of air is
increased because a diesel has no throttle blade nor is any measurable
amount of manifold vacuum created. A diesel of say 400 cubic inches uses
the same air a gas engine of 400 cubic inches would if it were run wide open
100% of the time.

--
Steve
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Remove the not dot from my address to abuse my email box
"L & D milligan" wrote in message
...

"Jacques Mertens" wrote in message
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It would not be sufficient for a gas engine but diesels need twice the
air
of a gas engine.
If the two engines are of equal capacity and turning at the same speed and
both are say four stroke engines then why would diesel require twice the
amount of air?