Quote:
Originally Posted by Phileaux4
He ran the engine at hwy rpm in park and measured fuel usage. The difference between that and actual mpg is friction and aero drag.
|
That sort of test is useless. You can't extrapolate from a no-load situation to a loaded situation by simply adding friction and drag. Throttle position, manifold vacuum (or pressure), ignition and fuel mapping, combustion temperature, and pumping losses will all be significantly different.