Originally posted by: Aharami
hmm. was always under the assumption that driving at a constant speed with windows up and AC to 1st setting provides best gas mileage.
That's the exact same thing I did when I got my best tank ever in my 92 Civic LX sedan (1.5L, stick shift). I was driving through Wisconsin, cruise set at 68-71 most of the time (speed limit 65--traffic was smooth, but just heavy enough that I didn't bother passing many people as long as they were doing over 65). It was a sunny day in the mid-70s. The windows were up, and the AC was on, set to recirculate (or "MAX AC" on some cars
😉 ) with fan on low. I got 42 MPG with that tank of fuel. With that car, I usually got 36-39 on interstate highway trips, depending on the weather and how fast I drove.
My test was neither planned nor scientific; I just rolled up the windows so that I could enjoy the stereo <milton>"at a reasonable volume"</milton>, and adjusted the AC so that I remained comfy. I attribute my record mileage in that car to the coolness of the day (as I said, mid-70s), because the AC compressor disengaged at least 75% of the time.
One varaible with my 42 MPG tank-full was the state I filled the tank in. It's usually
Minnesota or Illinois--this time I filled up in Wisconsin, where AFAIK, ethanol is (or was) not required in its gasoline. Ethanol-free fuel could also account for my ~10% better than usual MPG. (In other words, my test is scientifically invalid. Also not repeatable, because that old Civic was totaled a few years ago.)
