5 Tips to Get the Most Cool From Your Car Air Conditioning

Cold, hard facts about AC and how to make it work for you

detail shot of Volkswagen Atlas climate controls - A/C Photo: Courtesy of Volkswagen

Your car air conditioning works much better when you're actually driving because the faster the engine turns, the faster the AC compressor runs, which lets the system cool more effectively. Don't waste time and gas by letting your car run before you go.

When you start driving, turn on the air conditioner and open all the windows for 10 to 20 seconds. Even on the hottest days, the air inside the car will be much hotter than the outside air. You might think you're wasting the cooling from the air conditioner. But it will take that long for the AC to start cooling, so you'll actually be helping it cool the interior.

More on hot weather and cars

Your car's air conditioning system is going to get a workout trying to stave off the broiling effects of summer heat. Opening the windows may save a little gas, but for true comfort, you want to turn on the air conditioning and let it lower the humidity. Anyone can simply pick temperature setting. But there is an art to truly mastering the chill.

For that, the engineers at the CR Auto Testing Center have some handy tips to help you cool your car faster while burning less fuel.

2. Go Low

Setting to the lowest temp and adjusting the fan makes the car air conditioning more efficient, will dry out the air less, and can actually save some fuel. Why is that? In a typical AC system, the air is cooled to 38 degrees. If you set the temp higher, you're actually forcing the system to reheat the cooled air, which takes more effort and more fuel.

3. Don't Recirculate

If you have passengers in the back seat, consider turning off the recirculation mode. This takes air from the front of the cabin and pulls it back through the system, so even though everyone up front stays cool, the air in the back can get stale and hot.

4. Turn Off Stop/Start

If you’ve got a newer car that has an auto start/stop system, consider turning it off. This feature saves fuel, but for many cars it can keep the car air conditioning compressor from running when it shuts the engine off. In very hot weather, you can begin to notice the lack of cool air very quickly, especially if you're stuck at a lengthy stoplight or in stop-and-go traffic that's barely moving.

5. Make Sure Your Filter Is Clean

Next time you get the chance, check your cabin air filter to make sure it’s clean. A dirty filter prevents optimal airflow. In newer cars, these filters are relatively easy to check; if you see a lot of dirt accumulated on it, it's time to change it. You can save money if you can replace the filter yourself. In many modern cars, the filter is accessible behind the glove compartment.

Bonus: Automatic Climate Control

If you have automatic climate control, lowering the temp doesn't make the car cool off faster. Most systems will do all the fan and temp adjustments automatically, so you can just set it and forget it.