The message
from Ian Stirling contains these words:

Current car engines are about 25%
at best efficient, so 75% of power goes
out the exhaust pipe wasted.

No, 75% of "energy" is wasted.

75% of both.

I hate to agree with Dribble, particularly when he is only right by
accident, but in the instance above his answer does seem to fit the
facts. Some of the wasted energy departs via the radiator rather than
the exhaust pipe. :-)

BTW Dribble thought up a convincing definition for 'mountain' yet?

--
Roger Chapman
Seasons greetings to all, even Dribble.