How Much Difference in Fuel Consumption Between Using AC and Not Using AC?

[StHarrison]

Difference of 20%. The car's air conditioning accounts for about 20% of the engine's power, so using the AC consumes a portion of the engine's power, leading to increased fuel consumption. The specific increase in fuel consumption depends on the car's displacement and speed. Related details are as follows: 1. Principle of Increase: The car's engine provides power to the AC compressor, so when the cooling AC is turned on, the pressure on the car's engine increases, requiring more gasoline to burn for power. This is why sometimes when driving with the cooling AC on, the car's power feels slightly weaker, due to the increased pressure on the engine. 2. Heating AC: However, the heating AC is completely opposite. Because the engine generates heat, which produces warm air, this warm air serves as the source of power for the heating AC, akin to energy recycling. Therefore, the heating AC basically does not consume fuel. Many people prefer to set the AC to the lowest temperature for maximum coolness, which also increases fuel consumption.