How much fuel does running the AC on the highway consume?

[AddysonFitz]

Running the AC on the highway generally increases fuel consumption by about 2 liters. Reasons: The car's air conditioning accounts for about 20% of the engine's power. For a car that typically consumes 10 liters of fuel per 100 kilometers, running the AC will increase fuel consumption by about 2 liters. External factors: The higher the temperature, the higher the fuel consumption of the car's air conditioning. Dry weather also makes the car's AC consume more fuel. The higher the humidity, the higher the fuel consumption of the car's air conditioning. Using the car's AC during extremely hot and humid weather, such as in the dog days of summer, consumes more fuel than using it in dry weather, even if the external temperature is the same. Notes: Even when driving on the highway in hot weather, do not open the windows while running the AC. Opening the windows affects the car's speed, increases resistance, and leads to lower fuel efficiency and higher fuel consumption.