Does AC really use more fuel or does having the windows open (created wind resistance) burn more?
It’s summertime! Some of us wait all year for these sacred three months, while others feel as though they are literally burning in hell due to the heat. For those of you snow misers out there, I’m sure you’ve wondered what actually burns more fuel, running the AC or driving with the windows down.
The answer isn’t simple. Auto manufacturers claim that cranking up the AC doesn’t actually burn through as much gas as every body seems to think. However, the guys at Mythbusters tested these statements and discovered the opposite. When they filled two SUV’s up with 5 gallons of gas in each and drove at 45 mph on the same road, the SUV that ran the AC ran out of gas 15 miles before the one that drove with the windows down. This should come to no surprise. Running the AC uses power from the engine which depletes fuel in the tank faster. According the the Canadian Natural Resource Center, if you drive 9,000 miles annually, running the AC can cost you over $3,000 over ten years, now just imagine how these numbers would be adjusted to apply to your truck!
However, there is some good news! According to the United states Department of Energy, the more fuel efficient option depends a great deal on how fast you are driving. This is good news for many of you out there. When driving highway speeds, it’s more fuel efficient to run the AC as opposed to keeping the windows open since wind resistance is at its maximum on the highway.
There are obviously some other factors to take into consideration such as the specific size and weight of your truck, but for the most part, these stats will apply to any vehicle at scale.
All in all, the choice is yours, no one will blame you for prioritizing comfort over saving a few extra bucks for those long trips.