In article ,
tony sayer wrote:
uppose I have say a 100 kW engine then 25 % of that is useful driving
the wheels energy, so where would or does the other 75 kW go to then
surely not all as heat?..

Your engine will be very much more than 25% efficient at maximum power
output. The efficiency varies at different loads and engine speeds. When
it is idling, of course, it produces nothing like 100 kW. And so on.

--
*Wrinkled was not one of the things I wanted to be when I grew up

Dave Plowman London SW
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