Does Using Air Conditioning Consume More Fuel Than Driving?
3 Answers
Using air conditioning consumes more fuel than driving. It is recommended that car owners do not rush to turn on the air conditioning immediately when getting into a hot car. Instead, allow the car to cool down for a few minutes before turning on the AC to save fuel. When the air conditioning is in cooling mode: The compressor of the air conditioning system needs to operate, and the operation of the compressor requires power from the engine, which leads to higher fuel consumption. If it is too hot and the air conditioning is necessary, avoid setting it to the coldest level—moderate cooling is sufficient. The most comfortable temperature range for the human body is 20-25°C. Above 28°C, people may feel uncomfortably hot, while below 14°C, they may feel cold. When the car's air conditioning is in heating mode: The compressor does not need to operate; only the blower is working, so it does not consume much fuel.
Running the AC does consume extra fuel, and I can feel it every time I visit the gas station. That's because the engine not only powers the wheels but also drives the AC compressor. Especially in small-displacement cars climbing hills with the AC on, the throttle feels sluggish—engine revs soar but the car struggles to accelerate, burning fuel like crazy. I've tested it: urban driving with AC can increase fuel consumption by 15%, and the frequent compressor cycling at traffic lights makes it even worse. As for tips, keeping windows closed with AC on actually saves more fuel than open windows at highway speeds—open windows create massive drag. Modern cars with automatic AC systems smartly adjust compressor output, far more fuel-efficient than my old ride.
In my twenty years of working in auto repair, I've disassembled hundreds of air conditioning compressors. When the AC starts, the electromagnetic clutch engages with a 'click,' instantly adding 10-15% more load to the engine—equivalent to carrying an extra person while driving. This is most noticeable when idling with the AC on, as the fuel consumption gauge visibly rises. Last year, I helped a car owner test this: a 1.6L vehicle running the AC in city driving consumed an extra two liters of fuel per 100 kilometers. But compared to driving fuel consumption? Actually, below 60 mph, the burden of running the AC might be more fuel-efficient than flooring the accelerator to overtake.
