Here’s Why You Shouldn’t Use Your Car Air Conditioner

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There are few things more uncomfortable than a hot car on a humid day. As summer reaches full swing and temperatures rise, you’ll invariably crank up your car air conditioner more and more. But if you’re trying to save fuel and money, you may want to reconsider turning the car air conditioner on.

“On scorching days, the cooling system has to work doubly hard to control the engine temperature, and having the AC on also increases the chances of overheating, especially in older or poorly maintained cars,” says Joe Giranda of CFR Classic. Conversely, “cutting down on using the AC decreases the stress on essential systems, optimizing the vehicle’s performance and longevity.”

Here are a few more reasons to rely less on your car’s air conditioner.

Do Car Air Conditioners Burn More Gas?

There have been multiple debates on which method of vehicle cooling is more fuel efficient: air conditioning or driving with the windows down. There’s no doubt both cause more fuel to be burned. The question is, which burns more?

Open windows increase drag while driving, and running the A/C burns fuel to run. Eager to prove conclusively which option had greater impact on overall miles-per-gallon (mpg), the Society of Automotive Engineers (SAE) and General Motors did a controlled study comparing the fuel efficiency of driving with the car air conditioner on to driving with the windows down.

Driving With Your Windows Down

After comparing cars at speeds of 31, 50 and 68 mph in 86 degree F weather, they concluded driving with the windows down is more fuel efficient than running the A/C. The test also measured the fuel efficiency of closed windows and no A/C, which was significantly better on fuel than the other two.

Extreme Weather Temperatures

So if you need to cool off during a hot summer drive, consider rolling the windows down. Though some experts say A/C is the wiser option for fuel economy, multiple tests have shown otherwise. But the difference doesn’t appear to be as great when conditions aren’t extremely hot.

(Follow these directions to recharge your car’s air conditioner.)

Driving with the windows down isn’t the only way to save money on gas. We have a ton of tips for better gas mileage and fuel economy that are worth implementing.

FAQ

Does the outside temperature affect AC efficiency?

Yes, the warmer the outside temperature, the harder your AC system will have to work to keep you cool. Driving in slow traffic, towing or mountain terrain can also make it work harder.

“In front of the radiator is the AC condenser which is very hot, often over 250 degrees,” says Chris “Moose” Pyle, a master-certified technician with JustAnswer. “So you are pulling extremely hot air through the radiator and into the engine compartment with the fan.”

Are hybrid or electric vehicles affected the same way?

For electric or hybrid vehicles, running the AC in general depletes the battery, reducing your range by around 10 to 15%, says Giranda. But overall, “hybrid vehicles can handle the heat a tad bit better,” says Pyle. “A fully electric vehicle does not really get an effect from high heat; extreme cold is what attacks the electric models.”

About the Experts

• Joe Giranda is Director of Sales and Marketing for CFR Classic, where he’s worked as an automotive expert for 23 years.
• Chris “Moose” Pyle is a master-certified technician with 20-plus years of automotive experience. He has also worked as an expert for JustAnswer, the expert on-demand platform, since 2006.