Aaronpc2010

does anybody know how much gas mileage is used with the a/c? Some vehicles it's better for the mpg to use the a/c and other get better mpg with the window down. Any thoughts?

Ricktwuhk

There is no vehicle that gets better gas mileage with the window down. AC impact, vs. window up, should be about 1 MPG.

F150ken

Yea, about my gut feel/experience 1 mpg.

tuflehundon

Mythbuster's did an episode on this. What they determined, was A/C with windows up hurt fuel economy below 40 mph, but helped above that number. Having the windows up above 40 helped with aerodynamics enough that the power loss caused by A/C use was negated. And the difference was 1 around 1 mpg.

mandingo32

And us Floridians could care less what that number would be. It's too damn hot here not to run the A/C.

tuflehundon

Ain't that the truth. A/C is optional up north. Down here Heaters are optional.

ibd2328

iTrader: (2)

Smaller enginges with less torque, I'm sure it hurts a larger percentage. When you get into V8's and all the rotating mass on the belt, probably <2mpg. Too many variables to test, but I would say the 1mpg-1.5 mpg is a good bet.

It's a compressor so it takes some energy to turn. I would say its on par with the engery required to turn the stock fan/clutch assembly.

white89gt

I would agree, 100%

kd4gij

In my 99 4.2 is about the same with or without ac. And as said here in Florida only a couple days with out ac. Now by heater is bypassed and don't miss it. Not worth pulling dash out for.

10thGenScab

If I remember correctly, I want to say they also compared driving with the tailgate down vs. up to see what the difference would be. And I think their modeling was done with a 10th Gen F-150 too.