Is it more fuel efficient to roll the windows up in the car and use the AC or cut off the AC and roll the windows down.

barker111

This guy thinks that the AC is worse. http://www.madsci.org/posts/archives/jul2000/963530602.Eg.r.html Jul 28 05, 6:30 AM

Arpeggionist

I don't know about fuel efficient, but it's certainly better for the battery to not have the AC running. Jul 28 05, 6:32 AM

diamond jim55

I'll be curious to see what others think. I've heard that it's actually BETTER to have the AC on and the windows up because there's less wind drag. Jul 28 05, 6:35 AM

barker111

It's a matter of aerodynamics vs. accessories. Driving the A/C compressor uses more fuel, but you'll notice the difference more in city driving (read stop-and-start) than on the open road. And frankly, driving with the windows down creates turbulence at any speed. The faster you go, the more turbulence, the more drag. Jul 28 05, 7:30 AM

SOTHC

I have just tested it out and found there was no difference. Tomorrow I will try it out with the engine running. Jul 28 05, 8:04 AM

louley

Its more fuel efficient to have the air OFF. The guys on the tv show "Myth Busters" acually took two identical cars,drained out the fuel, refueled, and took them out on a track. The guy with the AC on lost miserably! Jul 28 05, 10:44 AM

dejavucub4

I saw and agree w/ the Mythbusters.Hmm but I don't hany windows on my Harley. Jul 28 05, 11:09 AM

dejavucub4

Windows went down on my computer, So I went for a ride, It didnt affect my mileage a bit. Jul 28 05, 11:13 AM

diamond jim55

Good deal. Thanks for the answers. I love the MythBusters. Jul 28 05, 1:36 PM