Which is more fuel efficient - using your vehicle's air conditioning, or rolling down the windows?

I agree with Stefie, rolling the windows down is more efficient

Yes because with rolling down windows you can effect the efficiency by changing the speed of the vehicle. Plus id love to see someone roll down the window’s in an aeroplane ><.

I’d also say rolling down your windows, it might cause wind drag, but hopefully that’ll make you drive slightly slower….

resulting in safer roads!

depends how windy it is and how much force comes into the car but if you want me to work it all out your having a laugh ha ha.

at certain times better for the ac but other times itll be better to just put the windows down.

it just depends on the wind speed.

I believe that when going highway speed, using the AC is more efficient than opening the windows. When going slower, the wind drag is less, so it is better to open the windows then.

I’d say turning on the a/c is more fuel efficient than rolling down the windows. The drag of open windows on the car requires a lot of power to overcome; I’d be surprised if the a/c uses nearly as much. It’s true that slowing down may increase your fuel efficiency, depending on what speed you usually drive, but that has nothing to do with whether the windows are open or closed. Whatever your speed, you still have to move the car from point A to point B. At a high speed you fight strong wind resistance for a short period of time; at a lower speed you fight weaker resistance, but for a longer period of time. The effect of opening the windows is the same either way - and substantially more, in my estimation, that that of turning on the a/c. But I’m just surmising - same as the rest of you {:^P

P.S. If you’re flying an airplane (or an aeroplane), then I’m quite sure I’m right =D

Mythbusters played with this one and they found in their first test that the computer said it was more efficient to do it with AC on @ 55mph, but when tested at 45mph when they drove until their tanks were empty the windows down ran out of gas last, by quite a ways. Thats rather conflicting results.

They tested it again in the next season and found that under 50 mph its more efficient to leave the windows down. After 50 mph the amount of drag generated makes in more efficient to have the AC on.

I had to did up some of the specifics from Wikipedia: http://funadvice.com/r/1530vhbeqa2 http://funadvice.com/r/biu9rdikqip

AGREED!

If you’re only going 40 or under , having the windows down is better . But if you’re going more than that , having the air conditioning on is better . Thats what I heard because when the windows are down it slows your car down so you have to go a little faster or your just using more gas . . But I could be wrong .

rolling down the windows, it uses less energy

I’d use the AC on long, fast rides and the open windows whenever you just go and take the kids to school or go shopping at low speed.

I seen the same program & I agree. They also proved that in a pickup, better fuel efficiency with tha tail gate up as opposed to the myth of having it down

i guess rolling down the windows….