odd question

[ScottyB]

while me, boobies, feersty, and mike were riding back from VIR, mike kept telling me i didnt need to downshift going uphill, even if the engine was bogging. his reasoning was that downshifting only uses more fuel. i said no way, but mike insisted that fuel was added relative to rpm (mike, correct me if i quoted you wrong on that). needless to say i didnt downshift much to avoid getting yelled at :lol:

my understanding has always been that fuel is added based on throttle position, not rpm. as an example, if fuel were added based on rpm, an engine couldnt function, because as soon as you were to open the throttle, the fuel mixture would instantly go lean and the engine would die. also, by that logic, a civic SI, for example, would get horrendously bad highway gas milage because it sits at about 4500 rpm at a decent cruise.

please correct me if i'm wrong but im almost positive fuel is added to the engine based on increasing throttle position, not rpm. if this is the case, than if im going up a hill, and i have to use alot of throttle to keep the engine from bogging, than that is less efficient than downshifting to a higher rpm (which is better placed in the powerband) which would use less fuel since my engine makes more power at higher rpm, necessitating less throttle to achieve the same speed. everyone with me?