How does air conditioning affect fuel consumption?

Your car's air conditioner is an essential accessory to keep you and your passengers comfortable and safe in hot weather. However, it is driven by your engine and puts extra stress on your engine when it…

Your car's air conditioner is an essential accessory to keep you and your passengers comfortable and safe in hot weather. However, it is controlled by your engine and puts extra stress on the engine while it is running. This means that it increases fuel consumption (reduces fuel economy). How much does this affect fuel consumption? Answer: a lot.

How much will this affect my fuel consumption?

Please note that there is no single answer to this question, as many different factors come into play. The actual outside temperature will make a difference, as will the size of your engine, the make and model of your car, the condition of your air conditioning system, and more. However, the US Environmental Protection Agency notes that operating the air conditioner in very hot weather can increase fuel consumption by up to 25%, and the effect of using air conditioning in a hybrid or electric vehicle can be even greater.

The best fuel economy defense is actually quite simple - use the windows at lower speeds and turn on the air when you hit the highway. Of course, open windows increase aerodynamic drag, which also reduces fuel economy, but the effect is not as great as when the air conditioner is running at lower speeds.

Proper air conditioning and engine maintenance will also help improve fuel economy. Regular oil changes and clean air filters can significantly increase fuel consumption. Ensuring the correct level of refrigerant in your A/C system is also an important factor.