The AC vs. Windows vs. Sunroof debate

Mythbusters covered it – not once, but twice – and everyone from TVSquad to AutoBlogGreen has piled on the criticisms. Looking at the facts, we know two things: the AC’s air compressor does have a notable impact on fuel efficiency … but so does the impact of decreased aerodynamics when the windows are down at high speeds. Most auto enthusiasts agree with the show’s original findings. Keeping your windows down at lower speeds, and switching to AC on the highway, provides the most comfort while focusing on fuel efficient driving.

I’m not technical enough to really do any experiments of my own, but by asking around, I’ve gathered the opinion that sunroofs also work to cool the air of the car – both by sucking out the heat (because heat rises) and by allowing cooler air to enter the auto.

You could also just pretend to have a sunroof  and just feel cooler socially-speaking. And it won’t compromise the integrity of your vehicle. :p