Tips to Get the Most Cool From Your Car Air Conditioning
Cold, hard facts about AC and how to make it work for you
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 the temperature setting. But there is an art to truly mastering the chill.
For that, the engineers at the CR Auto Test Center have some handy tips to help you cool your car faster while burning less fuel.
1. The Best Way to Cool Your Car Down Quickly
2. Use the Lowest Temperature Setting
Setting the temperature to the lowest setting and adjusting the fan makes the car air conditioning more efficient, dries 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. For Passenger Comfort, Don't Use the Recirculate Function
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 in Hot Weather
If you have 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’s 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. How a Dirty Cabin Air Filter Impacts Airflow
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. The owner’s manual will explain how to do it. Save on filters by buying online or at a local parts store.
How to Use 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. This is not only a convenience, but it optimizes cooling.
How AC Impacts Fuel Economy
Using air conditioning consumes gas. In mild weather, if you can get by without it—especially with open windows—you’ll see incremental savings. But once it gets hot, having AC on to cool the cabin and lower humidity is a wise investment in your comfort and ability to stay alert while driving. Our tests show the trade-off can be 1 to 4 mpg, depending on the car, for using AC. We did not see a measurable impact from opening windows at 65 mph. (See other gas-saving tips.)
AC in Electric Vehicles
It is fair to question if EVs seen a range penalty from using air conditioning and/or ventilated seats in the summer. Consumer Reports has conducted a four-season test on a several EVs exploring the impact of outside temperatures. We found that among the four seasons, driving in a sunny, humid, mid-80-degree day saw the longest range despite using the air conditioner. So stay cool and comfortable, without concern.
