Does idling in neutral with the AC on consume more fuel?

[DeKira]

Yes, it consumes more fuel. Here are the detailed explanations: 1. Reason When the AC is turned on, the engine control unit increases the engine speed by approximately 100 RPM. This increases the engine's air intake, leading to more fuel injection and a richer air-fuel mixture. The engine computer uses this method to enhance engine stability. However, a richer mixture can result in incomplete combustion of gasoline. Prolonged idling with the AC on can lead to increased carbon deposits, causing the engine to consume more fuel. 2. Compressor The amount of fuel consumed by the AC largely depends on the type of compressor used in the car. If it's a fixed-displacement compressor, there's no need to adjust the temperature or fan speed deliberately, as the fuel consumption is almost constant whenever the AC is on, regardless of the temperature or fan speed. On the other hand, with a variable-displacement compressor, fuel consumption is related to the temperature setting.