Can you save money by simply opening your windows instead of running your A/C? Common sense dictates that this is the case.
Even in summer, you can simply open your windows and turn off your air conditioner in order to indulge in the summer breeze instead of baking alive with an A/C-less car that's like an oven inside.
Switching your A/C on obviously hurts your gas mileage like any other feature of your car that draws power by burning fuel and uses up electricity from your battery However, does the A/C burn gas more gas than keeping your windows down and open?
Things to Consider About A/C Fuel Consumption
- How Much Gas Does The A/C Use? Although turning on the A/C for any car results in burnt fuel, just how much fuel is burnt depends on the operation of your A/C compressor. It could be up to a five percent drop in gas mileage if you run your A/C during a scorching summer day with a car that's filled to the brim with passengers, for instance. For example, if you're driving a Volkswagen Jetta diesel car with a 90 horsepower engine, it consumes half a liter of extra fuel to turn on the A/C after 100 kilometers of driving.
- Does Your A/C Burn Gas More Than Open Windows? It depends on the speed of your car, driving habits, and the make and model of your vehicle more often than not. Even though running the A/C does burn gas, opening your windows can result in lost mileage and fuel too because the air from the outside results in an aerodynamic drag akin to what keeps you afloat when you have a parachute open. You want your windows closed when driving instead of down for this reason.
- The Open A/C Versus Open Windows Debate: Unbeknownst to most drivers, both the A/C and the open windows can result in extra fuel consumption, although if you're driving faster then the open windows will naturally use up more fuel due to aerodynamic drag. According to the Society of Automotive Engineers, their 2004 test with a full-sized sedan and SUV in two tracks shows that driving at 50-55 miles per hour with windows open can result in more fuel consumption than simply closing your windows and turning on the A/C.
- Open Windows Consume More When The Speed Is Up: According to the test mentioned above, the fuel efficiency of both types of cars dropped by 20 percent with windows down while the rate is merely 10 percent with the air conditioning on. However, according to a 2012 test by Consumer Reports, the Honda Accord's fuel efficiency dropped by three miles per gallon when the car ran at 65 miles per hour with the A/C on. Therefore, it's best to keep the A/C on when you're driving fast but keep your windows down when you're driving slow.