[QUOTE]Originally posted by lanbrown
[B] In a car with a fixed roof, if you open the window you generate more drag.

 

[QUOTE]Originally posted by mns2k
[B]I have noticed that my MPG's go up as the weather gets warmer.

 

Of course it is true. Most vehicles have a CAFE requirement and the automakers want to get the highest MPG they can, so they spend some time with aerodynamics.

Obviously speed is a huge factor, as if you are stopped, having the window down takes less fuel then sitting there with the AC on. Define city areas; some areas have a speed limit of 45 or 50. Compare that to rush hour traffic on an expressway that is bumper to bumper.

 

Have any links or references to proof? How are you so sure that the load put on the car in the form of drag (with windows being down) is more than the load put on the car by the AC compressor? Just because you believe it does not make it true.

 

Just as I expected...nothing to back up the bold claims...

 

http://www.aaa-calif.com/westways/1101/overdrive.asp

Aerodynamics, Part III. You've probably heard that using your air conditioner consumes extra gasoline. True, but not always. At low speeds, using the AC can cost you a couple of miles per gallon, says the API. Better to open the windows. At speeds over 40 mph, switch on the AC. The drag caused from open windows consumes more fuel than the AC. Better still, shut off the AC, close the windows, and use the fresh-air vents at high speeds.

Don't know about you, the only time I'm not doing 40 is when I'm stopped and many roads have speed limits faster then 40.

 

[QUOTE]Originally posted by STL
[B]I've heard people say that too, but I have never seen anything halfway official to back up that claim.

 

[QUOTE]Originally posted by STL
[B]It has to do with the gas mixture.

 

Funny, STL, I don't see you posting a bunch of links in support of your position either. It's easy to make that kind of demand when someone disagrees with you on the web. I've noticed however, that most of the time, those who make such demands, rarely do the same for their POV.

How about it?

Drive Safe,
Steve R.

 

Thank you Intrepid175. I was actually waiting for STL to say he wanted scientific proof and I was going to ask for proof that having the windows down didn't do anything.