Driving a car when it’s super hot outside isn’t much fun. Luckily, most cars have air conditioning. But here’s a question many drivers ask: does using the AC guzzle more fuel?
Let’s get straight to it: Yes, running your car’s air conditioning uses up more fuel. If you drive an electric car, it drains more energy from your battery. The reason is simple. The AC system needs extra power from the car’s engine or battery to do its job.
Gasoline and Diesel Cars
In cars that run on gas or diesel, the AC system has a part called a compressor. This compressor gets its power from the car’s engine. When you switch on the AC, the engine has to work harder. This extra effort means it burns more fuel.
How much more? You might see your fuel use go up by 5% to 10%. This amount changes based on how strong you set the AC and how hot it is outside.
Electric Cars
For electric vehicles, the AC system pulls power straight from the main battery. Using the AC will shorten how far you can drive on a single charge. This is especially true on scorching hot days.
You could lose about 5% to 15% of your total driving range. The exact loss depends on your car model and how often you use the AC.
Windows Down or AC On?
Some drivers think opening the windows saves fuel. This can be true at slower speeds. But if you’re driving fast, like over 80 kilometers per hour (about 50 mph), opening the windows can actually make your car use more fuel. Why? Because the open windows create more wind resistance. This makes your car work harder to push through the air.
The Bottom Line
Running your car’s air conditioning does bump up your fuel or energy use, usually by 5% to 10%. But on the highway, using the AC can actually be a smarter choice than driving with all your windows down. That’s because of how air resistance works.
To keep your fuel or battery use in check, try these simple tricks. First, open your car doors and windows for a minute to let hot air escape before you even turn on the AC. Then, use your AC only as much as you need to stay comfortable, without blasting it on full power.