Does idling with the air conditioning on consume more fuel?
2 Answers
Idling with the air conditioning on consumes more fuel. The principle of idling with the air conditioning on: The power output consumed by the air conditioning only accounts for a very small part of the engine's idling energy. However, when idling with the air conditioning on, the engine not only drives the air conditioning compressor but also needs to maintain the normal operation of the power steering and brake booster pumps. The latter two functions are completely unnecessary when the vehicle is parked, and keeping them running is a waste of power, which leads to significant fuel consumption. Hazard to human health: Running the air conditioning while parked is very dangerous because when the vehicle is idling or moving at low speeds, gasoline cannot be fully burned, producing carbon monoxide. If the air conditioning is in the external circulation mode, it will draw carbon monoxide into the vehicle, potentially causing carbon monoxide poisoning for the occupants. This is especially risky during traffic jams when the air conditioning's intake is directly facing the exhaust of the vehicle in front. Therefore, it is best to switch to the internal circulation mode during traffic jams.
I've been driving for many years and I'm quite clear about this. Idling with the AC on does consume more fuel because when the engine speed is low, the compressor requires additional power to operate, forcing the engine to work harder, which leads to increased fuel consumption. Don't underestimate this. In summer, if you're parked waiting for someone with the AC on in the car, the fuel consumption can increase by 20% to 50% over an hour, depending on the vehicle type—smaller cars are slightly affected, while larger vehicles show more significant increases. I once tested my SUV: idling for an hour without AC barely moved the fuel gauge, but with the AC on, it consumed about half a liter more. Not only does it waste fuel, but prolonged idling with the AC can also cause the engine to overheat and accelerate wear. I recommend minimizing idling with the AC on. If you really need to wait, it's better to turn off the engine for short periods or open the windows for ventilation—saving fuel and ensuring peace of mind.
