I fill up the tank at 20,800 miles, now I'm looking at 20,86x miles. Normally I would be between 3/4 a tank and full (or 7/8 a tank), but I'm only a notch or two away from full! And on top of this, I've been driving and acceleration fast! What do you guys think of this?

 

The A/C only effects MPG's when you are under 35-40 MPH. Well I take that back if you were to run your A/C off and your windows open at 35-40+ MPH it would be more effective to run your A/C because of the drag that the open windows cause. I do think that no matter what your A/C does effect your gas mileage just alot less when on the Hwy. IMO

 

yep they tested that on myth busters.

 

Yeah but it was with furds everybody knows gm is better.

 

yea, the gms would have went for another 24 hours

 

That test on mythbusters imo was flawed due to them taking the safety precaution of not wanting the exploders to roll over or something. had they tested them at a higher mph, i would bet that having the windows down would have had a much greater impact on the aerodynamics and mileage of the vehicles.

 

Uuumm, ok, I don't care about some test. I can see for myself I'm getting much better mileage with out the A/C, and like I said, I have been been driving and accelerating fast (no offense to anyone BTW). Normally to get the kind of mileage I'm getting now, I have to keep it under 1500 rpm.

 

Like I said before you will get better mileeage with your A/C off no dobut but if you have your windows down the drag on your truck is alot greater than with your windows up at high speeds. Now driving around down even if your windows are DOWN your mileage will still be better because there is less drag on the motor. Which is another reason e-fans help out and add power less drag on the motor!

 

I have noticed about a 3mpg drop by using my a/c this summer. I can't wait til it cools off.

About having the windows down - I have never noticed any measurable difference in gas mileage with the windows down or up. That goes for my car and my truck.

 

Hmmmm...I never notice a difference with a/c on or off, windows down or up, or when I put on e-fans. Always right around 13.5