Your car’s air-conditioning system has one job—to keep you cool. But during a summer scorcher, it may seem like it’s barely up to the task. And even at those times, it’s eating up gas: The EPA estimates that using A/C in very hot conditions can reduce fuel economy by as much as 25 percent for a conventional vehicle. (It also zaps battery life in electrics and hybrids.)
Here’s why: Whenever you flip the switch, the system pulls in air from either the cabin or outdoors, extracts the heat and moisture from it, and pushes it out through vents. And the heart of this system is a compressor, which draws energy from the engine. So whenever you’re using the A/C, the engine has to work harder—and you burn more fuel.
But a few easy tips can help you save gas—and money—while making you feel cooler faster. Here’s what the pros recommend.
Park Smart
A car’s A/C system can only reduce the cabin temperature by approximately 40 degrees on average, says Jill Trotta, head of industry advocacy and sales for RepairPal. (Though of course, the longer you drive, the cooler the air will become.) If you park in a shady spot, the interior will start out cooler and the A/C will have less work to do. If the cabin is warm, roll down the windows and let the hot air escape before you rev up the A/C.
Set It To Recirculate
“Recirculation is probably the best way to maximize the A/C,” says Trotta. The benefit of recirculation is that the A/C system is pulling air only from within the cabin. So if it’s roasting outside but you already have the cabin down to a pleasant 72 degrees, the A/C will have to chill only that cooler air within the car. You’ll save on gas, too: Once the interior reaches the set temperature, the A/C compressor will turn off, reducing the load on the engine.
Skip Pre-Cooling
It may be more comfortable to cool your car before you’re underway, but running the A/C when the car’s not moving is highly inefficient. “Air conditioning will perform optimally when there’s airflow, like when you’re driving down the road,” says Timothy Hatcher, director of technical operations for the Automotive Maintenance & Repair Association. So wait until you’re already cruising before you turn it on. In an electric or hybrid, pre-cooling reduces the battery life, so either avoid the practice or stay plugged into the charger when you do it.
Change Your Cabin Air Filters On Schedule
The cabin air filters remove dirt and dust from the air that comes out of the vents. When a filter gets dirty, it restricts the air trying to pass through, says Hatcher. So replace the cabin air filters according to the schedule in your owner’s manual, which is probably every year or two, or every 15,000–20,000 miles.
Don’t Ignore Leaks
The biggest misconception about A/C systems, says Hatcher, is that if they’re low on refrigerant, you just need to add more (a process called recharging). But the system is sealed; nothing should be going in or out. “Adding refrigerant isn’t normal, and it isn’t maintenance,” says Hatcher. “It’s an indication of some other issue.” If yours is low, visit a professional certified in air-conditioning maintenance and repair to check it out.
Another way to keep your cool (and peace of mind)? Download the GEICO Mobile app for help at your fingertips—from roadside assistance to help finding your car and more!
Read more: Check out these other smart ways to get better gas mileage.
By Julie Anne Russell
Rob says,
What about using those window vent covers that you either adhere to the door on top of the window or the more expensive ones that fit tight inside the door frame? So you can leave a small opening in the window and it’s supposed to vent the heat out, without letting the rain inside your car window. Would this product vent out any heat to make it worth purchasing?
Pnr says,
Very helpful info..
Charlene says,
Thank you that information was very helpful and appreciated very much. Have a blessed day.
Melanie says,
This is GREAT information. Thank you so much. I am now going to change my cabin air filters!
Larry Greggs says,
Thanks that was very helpful information Geico. Learned a lot
Gene LeFevre says,
Very helpful, never thought about recirculating or recharging.
Abel says,
Thank you for your tips
José Kuilan says,
The article about the aircondition I love it. I leave in Manhattan and we need to wait two hrs after they swept the street and I use the aircondition while I wait. I would do that no more. Thanks for the article lol.
Donna Dyess says,
I recently had a friend change the account fan out. So now it’s blowing but not cold. Did I lose all my freon when he disconnected the old one?
HELP
Jacquelynn says,
Great tips!!! Thanks again Geico
Albertha Beal says,
Thank you Geico for these helpful information
John says,
Thanks Gieco! Kansas weather is hot. Would keeping it in the garage help over night?
Joel de percin says,
Ok very good.
mike cosby says,
Makes more sense to blow out the hot stale air with a couple of windows partially open initially before you start recycling it.
I have recharged my Toyota myself 2 times in the last 11 years and 160000 miles and it works great.
Sam spade says,
Forget a/c lots of cars have been through floods watch out and be very careful the car was not a rebuilt from a flood it will never be right