Does Using the Air Conditioner in the Car Burn More Gas?

The main argument against running the air conditioner, however, is whether it burns more gas than rolling down the windows. With the windows down, a car becomes less aerodynamic. The air that shoots in through the windows creates additional resistance or drag. Increased resistance means the car has to work harder to maintain its speed. Even the experts' opinions vary widely, from 45 to 75 miles per hour, as to what speed makes the drag greater than the effect of the air conditioner.