A/C On vs. Windows Down

[ExplorerDMB]

I was watching MythBusters the other day and they actually had a good one that dealt with a vehicle. They tested an Expedition and hooked up a computer to test the effects of A/C on windows up vs. A/c off windows down. With the windows up and the A/C on Max, they averaged 11.7 MPG. With the windows down and the A/C off, they averaged 11.3 MPG. I found this to be very interesting. This "myth" has been asked plenty of times with many different opinions on it. Now, the test they did was with a driver and passenger -- that's it. It was done with ideal conditions. No real load was given.

Now, they put people in the vehicles on the last trip and filled both vehicles up with only 5 gallons of gas. One ran with A/C on, one with the windows down. The one with the A/c on ran out of gas quicker. 30 miles later, the one with the windows down finally ran out of gas.

So the verdict: with a light load (driver and passenger) it's better to run with A/c....with a load -- windows down all the way!! I thought it was some good information.

-Drew

 

[Doug]

I like watching Mythbusters but most of the stuff they do is hardly conclusive nor follow any sort of scientific process. As we know well from this site MPG between identical vehicles can vary, sometimes widely. While the stuff they do on that show is cool and I like to watch it alot of the stuff they do doesn't prove a thing.

 

[blueox]

Like Doug says MPG can vary greatly it may have been more accurate if they had done both tests on the same vehicle. It would have been nice to see if they actually did get both tanks completely empty before filling them with a measured amount of gas also.

 

[Jason94sport]

I saw that. Doesn't prove a thing. They also used one of the worst SUV's to test. Ones that don't get good milage & power bands are not good at 45mph.

 

[ExplorerDMB]

I agree with all of your opinions, but I really do think it's the same. Turn your A/C on - your engine works a little harder and you lose a little gas mileage. Put down your windows and cut the A/c off, you have one heck of a wind resistance. What I do is this; Highway driving -- a/c on. City/country roads -- windows down. And like one of the guys on mythbusters said about the computer that Ford plugged into the Expeditions -- that monitors the air flow and not really the fuel consumption. I guess you could sit all day long an look at fuel trims, but I'd rather not.

-Drew

 

[aldive]

I have tested the effect on mileage of AC on vs windows down.

In my testing, I have shown no discernible difference in mileage either way.

 

[ExplorerDMB]

Thank you aldive.

 

[TheFox88]

I agree with all of your opinions, but I really do think it's the same. Turn your A/C on - your engine works a little harder and you lose a little gas mileage. Put down your windows and cut the A/c off, you have one heck of a wind resistance. What I do is this; Highway driving -- a/c on. City/country roads -- windows down.
-Drew

This is exactly what i do as well.

 

[davidmmm69]

it was on today again.. and i thought it was tested on Explorers..
and they should have used the same vehicle. for the 2 tests..

 

[wingot]

heres what i do... if its hot, a/c on. if its not as hot, vent and fan on with a/c off. however, living in fl, a/c is almost always on.

 

[cybercreeper]

Windows XP all the way, oops i mean window up A/C on...LOL

 

[ExplorerDMB]

Windows XP all the way, oops i mean window up A/C on...LOL

I don't get it?

-Drew

 

[davidmmm69]

i was wondering th same thing

 

[CDW6212R]

Little difference, I agree with Al. Use AC if it's hot, regards,