How much fuel does a car consume when running the air conditioner overnight?
3 Answers
A car running the air conditioner overnight consumes approximately 16-20L of fuel. Under normal circumstances, a 1.5L displacement household car consumes about 1.6L-2.4L of fuel per hour when idling with the air conditioner on. Taking the average fuel consumption as 2L per hour, and calculating for 8 hours overnight, the total fuel consumption would be 16L of gasoline. Here is some additional information: Notes: It is important to note that it is not recommended to sleep in the car for extended periods. If you must sleep in the car, be sure to open the windows or sunroof slightly to allow ventilation. If all doors and windows are tightly closed, the concentration of toxic gases inside the car will increase, which could lead to the risk of suffocation. Idling: Idling refers to the state where the engine is "running without load." During engine operation, when the throttle pedal is at 0 depth, this state is considered engine idling. The engine speed when the transmission is in neutral (N) is referred to as the "idle speed."
It depends on the specific model and situation. I've been driving for over a decade and often spend nights in the car with my kids during summer. Take my old SUV for example - idling with AC on consumes about 1.5 liters of fuel per hour. If you keep it running all night for 7-8 hours, the fuel gauge drops by about one and a half marks, totaling over 10 liters. However, newer hybrid models are much more efficient. My friend's hybrid Camry only uses 2-3 liters for overnight AC use. The key is to keep windows slightly open for ventilation - never do this in an enclosed garage as carbon monoxide can be deadly! For precise calculation, note your fuel gauge reading when parking, then check the difference next morning.
I conducted a test using my 1.8L naturally aspirated sedan when the outdoor temperature was over 30°C. With the AC set to the lowest temperature and maximum fan speed, the engine idled steadily at 800 RPM. The result showed it consumed about 1.2 liters of fuel per hour, totaling approximately 10 liters overnight. Actually, fuel consumption mainly depends on three factors: engine displacement determines the base consumption, lower temperature settings and faster fan speeds increase fuel usage, and the type of compressor also plays a role. Many new cars now use variable-frequency compressors, which can save about one-third of the fuel compared to older fixed-frequency ones. It's best not to sleep in the car overnight, but if you must use the AC, choose a shaded spot to reduce the extra workload caused by direct sunlight.
