Which would use less fuel?

[CaptainHenreh]

Well Rex, this is good for discussion, how bout the waste of energy pushing out more exhaust from the cylinders at WOT, could that possibly offset the throttle plate?

Well, exhaust is alot easier to get out than clean air is to get in. Exhaust is hot and ready to expand, most of it goes out without the piston's help, hence why 2 strokes work, and why they make more horsepower than the same-size 4 stroke. (ok, generally)

I do see your point, though. That's why this question is so difficult. Obviously, revs play a HUGE factor in fuel economy, which is the other reason why I chose the option I did. If that weren't the case, than an overdrive transmission would be pretty stupid, don't you think?

[Maengelito]

I agree Mike, and I doubt it's very accurate. But, my above claims were made with it at sustained speeds/throttle. So, whereas the exact numbers might not be right, the position is enoguh to make some conclusion.

The only variable I change is the load. I keep the throttle position and speed the same. In such an experiemnt, when going up hill at 70mph in 5th vs 4th, most often 4th reviels the higher MPG.

YMMV (ha ha ha)

the bmw gauge as far i understand is basically a vacuum gauge much like a boost gauge except its not going into positive pressure. i think the problem with the proposed question is that i'm sure the programmed fuel maps for our cars are not linear. WOT is probably going to dump as much fuel into the engine as the pump and injector allow making the "mpg" gauge show very low mpg. however, half throttle is not necessarily going to dump half the fuel the pump and injectors allow because it'll depend on engine speed. but is that half throttle thats dumping lets say 75% capacity for the fuel system spinning the engine at twice the engine speed as at WOT? so as stated before, it depends...

[Mike]

so i tested both cars last night... s2k lugs until 2700rpms, civic lugs until 2000rpms... both in 5th gear.