Fuel Efficiency With A/C vs. Windows Down

Summer is in full swing, and it sure has been a warm one. Everyone wants some relief from the heat while they’re in their car. You really have two options, turn on the A/C or roll down the windows. Unfortunately, both of these options do come at a certain expense. The cost will generally come in terms of fuel efficiency. When you roll down your windows, your increase the drag on your car by severely cutting down the aerodynamics and increasing drag. On the other hand, the air conditioner makes your car’s engine work harder which increases the amount of fuel used. It comes down to specific circumstances and what works best at that particular time.

Rolling Down the Windows

The loss of fuel efficiency from rolling down your window is generally going to be less than using A/C as long as you’re on city streets and NOT the highway. However, it can be impractical sometimes. For instance, if it is already sweltering outside, rolling down your windows may not be so helpful because you will only be taking in warm air if you’re not continuiously moving fast.

We really advise against driving around with your windows down if you’re going to be traveling at high speeds or the air outside is so hot that you can barely find relief. At high speeds just keep the windows up or with a slight crack. Just picture your car, think about how smoothly air flows over it. Now put massive holes in the sides and think about how good those areodynamics compare.

Air Conditioning

A lot of people turn to their air conditioning right off the bat, it’s always the first thing they go to. The air conditioner provides immediate relief. It also tends to just feel more crisp and refreshing than air from your windows will, and you have precise control over it. The only disadvantage of it is that it taxes extra power from your engine to power that cooling. We reccomend not using your A/C unless you’re traveling pretty quickly, like on the highway. Your engine and wallet will thank you for it!

Finding that Balance

When it comes to choosing which method is going to be best for you, you need to stop and think for a moment. When you use the right methods at the right speeds you can count on saving that much more gas and money. The best general rule of thumb is keep the windows down when driving through the city, and keep them rolled up with the A/C going when you’re traveling at high speeds like on the highway.

A portable fan is also a fantastic option. It just pulls energy from your car battery, which is already getting recharged by your alternator so you’re not losing much there! Surely you’ve seen fans mounted in busses and other big vehicles, they’re amazing! You also aren’t stuck in just using these few methods as we laid them out. If it’s super hot out and you’re driving in the city, nothing is wrong with keeping your windows up and pumping the A/C on occasion, the most important thing is your comfort.