It’s natural to want to crank up your car’s air conditioning on hot summer days, but is it true that the AC uses more gas? Does wind resistance have an effect on gas mileage?
Do I save more gas with the AC on and the windows up or the windows down and the AC off?
What’s better for fuel economy- AC off and windows down or windows up and AC on? Well, it depends on the speed. Around town you’ll probably get better fuel economy if you turn the AC off and roll the windows down. But as soon as you start traveling at highway speeds then wind resistance plays a big part in fuel economy and you’ll do better by rolling the windows up, which maintains the aerodynamics of your car and turning the air conditioning on.