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andrew andrew is offline
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Default Graph of car fuel consumption versus speed

Roger wrote:

It is more than 40 years since I did any thermodynamics and we didn't do
much on IC engines anyway but through the mists of time ISTR that an IC
engine is most efficient at max bmep (brake mean effective pressure
IIRC) and max bmep equates very closely to max torque.


Me too, that's why it should be better to get to your target speed by
keeping the revs in the max torque band as you change gears, which implies
full throttle but I suspect the fuel map is such that its best to back off
from this a bit.

AJH