Is it more fuel efficent to drive with the windows open or the A/C on?

Question

Is it more fuel efficent to drive with the windows open or the A/C on?

Answer 1

mythbusters did a show about this. if you ride with the windows down and the air off you may get a little more out of your gas, but maybe about a mile or less. its not a matter of fuel efficiency, but which one you like more.

Answer 2

I've herd that it is better to ride with the windows open and the air off, but i've also herd that with the windows open it creates more risistance agenst the car, that causes it to waste more gas

Answer 3

The AC is the biggest drag in stop-and-go driving. Some cars will have a switch that cuts out the compressor clutch during acceleration, but not all.

When cruising at a steady speed it makes no difference.

Answer 4

They had a thing on the Today show that proved that the AC is more efficient then having your windows down. When they are it produces more drag and isn't as aerodynamic as when the ac is on.

Answer 5

It depends on the model of car driven. Air drag with open windows related to the ac compressor drag on the engine.

More likely with modern design of ac systems and the efficiency of modern aerodynamic design. It's better ac on with windows closed.

In older cars windows down ac off. The ac wasn't that great to begin with and the aerodynamics weren't ether.

Answer 6

it depends on the speed you are going.

at low speeds windows being open will not cause much drag on the vehicle so that would be more efficient.

however at high speeds (70mph plus)  windows being open will consume more gas because you are putting a huge drag on your car.

there are so many myths about saving gas its crazy but ive tried going with the windows open down the highway myself and i used more gas then with just the AC on.

as another tip, leaving a car idling for more than 30 seconds uses more gas then restarting the car.