So, I realized that I'll get better gas milage if I leave my windows open below a certain speed and use the AC @ higher speeds...but what speeds?

For me, normaly driving speed is normally 55. 70+ on the interstate. Anyone know what the accepted "highway" speed is?

(I realize that the difference really isn't that much, but I'm only getting 29mpg with a CVT right now!)

at 55 mph, windows up. thats where the drag becomes grater than the pull from the ac

thank you mythbusters

Althalus wrote:So, I realized that I'll get better gas milage if I leave my windows open below a certain speed and use the AC @ higher speeds...but what speeds?

For me, normaly driving speed is normally 55. 70+ on the interstate. Anyone know what the accepted "highway" speed is?

(I realize that the difference really isn't that much, but I'm only getting 29mpg with a CVT right now!)

Countless people have tried to perform this test and the test results are always pretty close, hence the constant debate. I watched that Mythbuster episode and I enjoy the show as a whole, but you have to admit that some of their test aren't that scientific. Modern vehicle cycle the compressor on and off and cool more efficiently than older vehicles. Lots of people like to think you're driving down the road and since you have cool air hitting, the A/C is on, but it cycles on and off. The proven methods below will save more gas than driving with the windows up and the A/C off any day.

Proven Methods:-Make sure your tires are inflated properly-Remove excess weight from your vehicle-Change your driving habits. No jack rabbit starts and coast more than accelerating.-Slow Down, more speed=more rpm's=more gas-Shut off the car when not driving. If you're waiting for someone, don't leave the car on. Shut it off and save the gas.

Why don't you just be comfortable and use the AC if you need it? Isn't that worth that $0.10 you'd save by rolling your windows up and down? Having the right tire pressure and the other practical standard solutions seem like a much better way to go.

Well, it's not really hot enough to use the AC anymore, and I love driving with the windows down, so depending on how much of a difference there is, it doesn't really matter to me.

take it from a hypermiler, just use the ac when your on the highway. Its a quieter ride and if you want to be cheap, just turn on the defroster on cold. It will cycle the A/C on and off instead of running it continuously.

Plus its good to use your A/C lube it up once in awhile since it has mechanical parts of its own.

All but about 200 of my 1200 Versa miles have been using a/c, which includes city driving.

And I'm still hanging around that 30 MPG average mark.