Is more gas conserved by using the A.C. or rolling down the windows (when on the highway)?

Definitely rolling down the windows. Air we breathe is free and circulates better. Temperature is always perfect with natural air.

Using the A/C in your car, DOES NOT USE MORE GAS. IT IS AN ELECTRICAL ISSUE. When your car’s engine is running, it is turning the A/C pulley as well. When the A/C is switched on it magnitizes a clutch and coil to engage the compressor. Keeping the windows up at highway speeds is more aerodynamic, but if you are in a traffic jam, it is best to turn off the A/C and roll down the windows to avoid overheating the engine.

More fuel is conserved by rolling down the windows!
The ac in a car is operated by a compressor. You car hear it engage when you turn in on. The compressor puts a huge amount of ‘drag’ on the engine greatly reducing fuel economy. Rolling down the windows will create drag by reducing aerodynamics but not to the extent of the ac compressor. Good question!
Jeep freak is dead wrong!
Try it for a week with each to prove this!

windows down is cheaper. do you use more energy with an electric shaver or just a blade?

A.C.gets a slight advantage.

Mythbusters tested this. They found that it’s better to roll the windows down until you reach a certain speed and after that roll them up and use the AC. I can’t remember what the speed was, I think it was 50 MPH, but I’m not sure.

Jeep Freak is wrong. Using AC uses more gasoline. There is almost no drag when you open your windows.

I drove for 1400 km with AC off, and had half a tank of gas left over on my trip. I did the return trip (again 1400 km) with AC on (it was very hot that day), and I had to make an additional stop for gasoline.

Steve is right, I believe the speed was 45 – 50 mph