A/C or Windows Down Better for Gas Mileage? | Columbia HVAC
Written by Columbia Heating & Cooling

A/C or Windows Down Better for Gas Mileage?

Planning a fun summer road trip? When you head to the gas pump, don’t be surprised to find higher than average prices. Private analysts and the U.S. Energy Information Administration (EIA) predict the most expensive driving season since 2014.

This leads us to the question, how do you conserve gas during the hot summer months? Is it more efficient to leave the windows down or run the air conditioner with the windows up? Both methods of cooling reduce gas mileage. The amount of extra fuel consumption will depend on the type of car you’re driving and your rate of speed. But is one method more inefficient than the other?

Rolling Down The Windows

The reason rolling down windows can be inefficient is because it increases wind resistance, also known as “drag.” The higher your speed, the more drag your car will have. Depending on the size and shape of your car, drag can have more or less of an impact. Larger and boxy cars have more drag, while shorter and streamlined cars have less resistance.

AC Turned On

Vehicles get better gas mileage when the air conditioner is turned off, and the windows are rolled up. A/C alone reduces gas mileage slightly. But fuel efficiency is much worse when both the air is on, and the windows are rolled down.

The bottom line? Try to limit using your air conditioner to highways and highway speeds. Roll down your windows while driving around town and stuck in traffic.

6 Tips for Conserving Gas During the Summer

1. Reduce your speed
Fuel consumption increases significantly when you’re traveling faster than 50 MPH.

2. Avoid hauling heavy cargo
Strapping cargo to the roof or pulling a trailer can create drag, making your car less efficient.

3. Inflate your tires
Making sure your tires are properly inflated can improve your vehicle’s fuel economy by 3.3%.

4. Release hot air from your car before leaving the driveway
Airing out your vehicle before you leave will reduce the need for heavy A/C usage while you’re on the road.

5. Turn off your engine when parked
A car can use anywhere from a half gallon to a gallon of gas for every hour it idles.

6. Start the A/C after you’ve started moving
Avoid running the A/C while your car is idling.

We may not work on cars, but we’re experts when it comes to efficient air conditioner usage. If you need to replace an old, inefficient air conditioner in your home, we have top-of-the-line products and HVAC experts at the ready to help you with any of your cooling needs. Give us a call today for a FREE replacement quote!