"Dave Plowman (News)" wrote:

In article ,
Johannes wrote:
Strangely enough, cooling though the radiator is just as important as the
heating in the combustion for achieving high efficiency. You can only
extract mechanical energy between two temperatures; the larger the gap,
the more efficient.

That's a bit of an over simplification. Engines don't run at their most
efficient until up to temperature. Probably to do with proper atomisation
of the fuel.


Indeed, this is abstract thermodynamic theory that was fully developed in
the 19'th century. It is unrelated to a particular engine as long as it's
in the business of converting heat to mechanical energy. The maximum
possible efficiency of an engine is (T1-T2)/T1 .