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
Bruce A Grant says,
thanks, for that information. was very helpful.
Hilda torres says,
U r information help me a lot, thank you.
Dan says,
Not bad but think about it.
Unless you are parked in the shade or garage, your can interior can get up to 160 degrees inside. Opening the doors for a little extra time or rolling the windows down can allow some of that hot air to escape but the interior and seats are still hot like muffins. They will still be warming the interior air until they equalize. And the interior air will still be hotter than the air outside. So you need to get that hot air out of your car and to do that you need to bring (relatively) cooler air in from the outside so that the hot air can vent out. It’s more efficient to cool 100 degree air from the outside than 140 degree air being warmed by the seats and walls.
So, start your air conditioner on the normal setting so that it can push the extra hot air out out the rear vents. Then, once the interior and air is about the same temp as outside, switch over the the MAX setting so that you can recirculate the interior air as it is cooled BELOW the outside air temp.
It only takes a few minutes but truly is more efficient.
Sytheanah says,
Thanks for the tips, it was very informative
Randy Fike says,
Another important point is that your AC is either ON or OFF. This means you shouldn`t try to lessen the load on the AC by not putting it on full cold. Some people think that by not putting the temperature setting to full cold that they are making things easier on the system and saving gas. In reality, the AC is working just as hard as if you had it on full cold. The only difference is you are mixing in hot air from outside before it enters the cabin. So – you end up burning the same amount of gas and don`t get the full benefit of the AC.
Mahmood Anwar says,
Thanks for good information on the air conditioning of the vehicle.
Randy says,
Re circulation may be the best way to maximize the A/C most of the time. But when you first get into a hot car, you can help your AC a LOT by first setting your vents to the outside air position for a minute or so. Especially if the car has been in the sun, this is simple common sense. If the outside air is 90F, and the air in your car is 105F, you can move the cooling process along a lot faster by changing the the air first. Try it, and you’ll quickly see the difference. After a minute or so, switch to the recirculate position, as this article advises.
Marylee March says,
Thanks for the tips very helpful
Janice Watlington says,
I really loved your tips on ways to save fuel and to help maintain your auto better.
Thanks
Duane Laurent says,
An excellent way of saving gas and our environment.
Marsha Sizemore says,
Thanks for the tips!!
Jorge Hernandez says,
Thank you, that is very useful.
Elizabeth says,
Thank you this was helpful on the A/C I thought it wasnt normal and you just confirmed it..
Tony Cody says,
Thanks for the tips. Much appreciated.
Geary Baxter says,
I carry a small unit called “Bolt”. I have had totally dead batteries and this thing started my truck in 15 seconds. They aren’t cheap but they are worth every penny.