How Much Fuel Is Wasted by Running the Air Conditioner for One Hour Without Turning Off the Engine?
3 Answers
Fuel consumption when idling with the air conditioner on: Under normal circumstances, if a car consumes 10L of fuel, turning on the air conditioner will increase fuel consumption by approximately 2L. The impact of fuel consumption and whether the air conditioner is on is significant, and the effect varies with different fan speeds. Precautions for idling with the air conditioner on: 1. Fuel consumption is relatively high when idling with the air conditioner on, generally reaching around 2L/h. Therefore, idling for extended periods with the air conditioner on will consume a considerable amount of fuel. If the car's fuel level is insufficient, it may run until the engine shuts off. 2. When idling, incomplete fuel combustion produces a large amount of carbon monoxide. The longer the idling time, the higher the concentration of carbon monoxide around the vehicle. Prolonged idling can lead to extremely high carbon monoxide concentrations inside the car, which can cause carbon monoxide poisoning or death if someone is inside, resulting in safety hazards. 3. Incomplete fuel combustion during idling can lead to engine carbon buildup. Severe carbon buildup can affect the car's normal startup, reduce engine power, increase fuel consumption, and cause excessive exhaust emissions. 4. Prolonged idling emits a large amount of exhaust, exceeding PM2.5 standards, polluting the air and causing significant environmental damage.
My old car wastes about 1.5 to 3 liters of fuel when idling with the AC on for an hour, depending on the car's size and age. My compact car with a 1.6L engine consumes around 0.3 liters per minute at idle. When the AC is running, the compressor kicks in, forcing the engine to work harder and adding another 0.5 to 1 liter of fuel consumption. After an hour, that's at least 2 liters of fuel gone! Converted to money at current gas prices, that's dozens of yuan down the drain. The real issue is, this not only wastes money but also causes carbon buildup, which harms the engine over time. So now when waiting, I try to turn off the engine or step outside for fresh air—saving money, being eco-friendly, and extending my car's lifespan.
Do the math – keeping the engine running with the AC on for an hour really burns through fuel. From my experience, an average sedan wastes at least 2 liters of gas, while an SUV might guzzle up to 4 liters. At ¥8 per liter, that's ¥16 to ¥32 literally evaporating per hour – enough for a takeout meal. The AC's compressor forces the engine to work harder, draining fuel rapidly. This also increases emissions, polluting the air. Long-term, it's a bad habit – I once timed it: half a liter gone in just 10 minutes of idling. Better alternatives: use fans, park in shade, or ventilate by opening hot car doors briefly. Every drop saved counts. Economically, fuel efficiency equals money saved, plus it's kinder to the environment.
