Does Running Your AC Effect Your Gas Milage?

What Is a Car Insurance Deductible?
August 14, 2022
Show all

Does Running Your AC Effect Your Gas Milage?

car air conditioning

Many people wonder whether or not running a car’s air conditioner can affect the vehicle’s gas mileage. Historically, this has been an unresolved question, but as technology improves and fuel efficiency standards are set higher, it is worth revisiting this issue.

Fuel efficiency is a major concern for many drivers. Even something seemingly insignificant as using your car’s air conditioner can significantly affect fuel economy.

The air conditioner functions as a heat pump. It uses the car’s engine to crank out cold air while heating the car with its refrigerant. The circulation fan pulls air through the condenser when you turn on your air conditioner. The hot engine heats this air, eventually evaporating into the outside air.

As this water vapor is pulled out, the vehicle’s air conditioner has to put coolant back into your car. After the hot air passes through the engine, the coolant heats up and changes back into the water. This process then repeats over and over again.

How Much Does Air Conditioning Affect Your Mileage?
Depending on several factors, the amount that runs the air conditioner affects your gas mileage. These include the size of your car, the outside temperature, and the kind of AC system you have.

Specifically, air conditioning affects gas mileage varies from car to car. It differs due to size and engine output more than anything. Some estimates suggest that running the air conditioning in a big SUV can drop gas mileage by up to 20%, while this effect is less in a small car.

In addition to your vehicle’s effects, outside factors can also impact fuel economy. These factors include:

• Climate: cold weather has been shown to cause a greater drop in gas mileage than hot weather. On the other hand, extreme heat can harm fuel economy. When the outside temperature is very hot, the evaporative cooling of the air conditioner cannot keep up with the heat, causing the vehicle to run hotter than normal.

• Humidity: on extremely humid days, your car’s engine and AC system will have to work harder to cool you down. If you are in this situation, it is advised that you do not turn on the air conditioner while driving.

• Size: larger vehicles such as SUVs have larger engines and require more time to cool off. That means they have a greater chance of running hotter than smaller cars.

These factors and many others are considered when estimating the overall effect on gas mileage. However, three main elements determine how much the air conditioner affects your car’s fuel efficiency. These factors are:

1. Coolant Efficiency: The air conditioning system needs a certain amount of water to function correctly. When a vehicle’s air conditioner runs, the coolant level drops and eventually needs replenishment. If there is an insufficient amount of coolant, it can lead to decreased efficiency when cooling.

2. Condenser Efficiency: Condensation occurs in the engine, and reduced condenser efficiency means the system does not work well in turning hot air into cool air.

3. Engine Load: The engine has to work harder to produce the same amount of power when the air conditioner is running due to increased engine component resistance.

Conclusion
So, consider these considerations the next time you drive in the summer. If you are in a hot environment but not particularly hot outside, it may be better to drive with the windows open. That will reduce the load on your engine.