Running A/C vs Rolling Windows Down- Which Is More Gas Efficient?

When deciding whether rolling down your windows or using your vehicle’s air conditioner is a better option to keep cool, yet fuel-efficient, you need to consider the type of vehicle being used. A study conducted by the Society of Automotive Engineers (SAE) found that driving with the windows down in vehicles with large V8 engines showed an increase in the amount of resistance caused by wind getting trapped inside the vehicle and a drop in fuel efficiency because of this.

Also, if your vehicle is more aerodynamic it will have more of a problem with this resistance. Aerodynamics is a factor because the air will move more freely over the surface which can cause faster speeds and more trapped air leading to resistance. This resistance is what makes your car work harder and use more fuel to keep it in motion.

The Speed Factor

When you are driving at higher speeds the wind speed is also higher than if you are going at lower speeds. The faster the wind the more air that is likely to get caught inside the vehicle.

It is advisable by some that having the windows down while going speeds less than 45 miles per hour would be more cost-effective fuel-wise because less air would become trapped in the vehicle pushing back on it than it would be at higher speeds. To run your air conditioner, takes a good bit of energy, therefore, taking away from the other energy-hungry mechanisms that need the power to work efficiently.

So Which is More Efficient?

Ultimately the answer depends on your preferences and the overall maintenance of your vehicle. There is some evidence that says it increases fuel use when the air conditioner is used, but on the other hand if windows are down there is also drag, which also increases fuel consumption.

According to some mechanics, as long as you keep your vehicle all-around efficient, it will save on gas in all driving conditions whether hot or cold. It’s completely up to you, ice-cold filtered air on your face, or the fresh breeze blowing through your hair.

Need Your Vehicle’s A/C Repaired?

If you need A/C repairs on your vehicle, contact South Park Service Center for your heating and cooling system repair. We’ll help you keep cool this summer!