Not sure if this should go here...But...

Hey there…
Ever since I got the sun roof in my car, I have been running with the top open, and windows down (plus we are having really nice weather here in SOUTH FLORIDA)…so anyway…

This may be stupid, but do you think, that around the city, it will

A: Affect my gas mileage in a negative way
B: Not affect my gas mileage
C: Only affect my gas mileage if the top is open, and the windows up.

I figure on the highway, it would make it worse, what with the drag it would put on the vehicle.

Now, another question.

I sometimes will open the roof, and keep the windows up, and use the A/C…this way, I get some fresh air in.
I rarely do this. But I wondered if this was a Bad Thing™ to do, or if it makes no difference, other then it might eat up more gas.

Any thoughts?

 

I read somewhere that running with the windows down uses as much gas as using the a/c with the windows up. personally do what you like. I run with the windows down all the time. my wife yells at me to turn on the a/c when she's with me. I tell her this is FREE a/c, just drive faster if you want it cooler.

 

Myth Busters did a bit about this question. They drove identical Ford Explorers around a race track at a constant speed, one with the windows down and no A/C, one with the windows up running the A/C. The vehicle that did not use A/C went a few more miles than the A/C vehicle.

 

I agree - running compressor takes energy - uses fuel!

 

^^^Amen to that Brother!

 

I can vouch for this.

On a trip to down to Orlando in my old '03 Eclipse GTS I got about 32-33 mpg (all highway driving and it was rated between 21-30 anyways). Ran it with A/C a few times and it dropped down to 28-30 mpg.

 

Thanks! Makes me wonder...I guess when it's real hot, just use the A/C...

 

I'm forced to use A/C most of the time because of the noise.

I get this deafening "beating" sound from the wind through the windows when driving over 45mph...