What is the fuel consumption of a diesel car idling with the air conditioning on for one hour?

[JulianaLee]

Diesel car idling with the air conditioning on for one hour consumes approximately one liter of fuel. Additional information: 1. Vehicle air conditioning: Vehicle air conditioning consists of a compressor, condenser, throttle element, evaporator, fan, and necessary control components, used to regulate the temperature and humidity inside the car, providing a comfortable environment. 2. Working principle: The compressor sucks in low-temperature, low-pressure gaseous refrigerant from the evaporator. After compression, the temperature and pressure of the refrigerant increase, and it is sent to the condenser. The high-temperature, high-pressure gaseous refrigerant transfers heat to the outside air passing through the condenser and liquefies, with its temperature and pressure decreasing. The low-temperature, low-pressure liquid refrigerant absorbs heat from the air inside the car passing through the evaporator and evaporates, turning into gas. Through the circulation of the refrigerant in the system, it continuously absorbs heat from the air inside the car and discharges it to the outside air, gradually lowering the temperature of the air inside the car.

[OliviaDella]

Oh, I remember when I used to drive my diesel SUV, idling with the AC on for about an hour would consume roughly 1.5 to 2 liters of fuel, depending on the engine displacement. My 2.0-liter engine burned even more fuel in summer when the AC was at full blast, nearly 2 liters. Once the AC compressor kicks in, the engine has to work extra hard, and idling already consumes more fuel. If you're waiting by the roadside for an hour, at a fuel price of 7 yuan per liter, you'd spend around 15 yuan, which isn’t very cost-effective. Long-term idling like this can also lead to carbon buildup, making the engine prone to issues. Nowadays, I only use it briefly in emergencies, like during a traffic jam on a scorching day. Otherwise, stepping out for fresh air or turning off the engine is a smarter choice. Also, keep an eye on the AC filter—if it’s clogged, efficiency drops, and fuel consumption rises. Regular maintenance can prevent minor issues from turning into major repairs.

[SanJuliana]

As a driver with over a decade of experience operating diesel vehicles, idling with the AC on for an hour does consume a significant amount of fuel. Based on my usage, a 1.6L diesel sedan averages 1.2L per hour, while a 2.5L pickup truck can reach up to 1.8L. Higher fan speeds lead to increased fuel consumption; for instance, using the heater in winter for half an hour only consumes 0.5L, but cooling in summer for an hour can cost nearly 2L. This translates to fuel expenses of 6-14 yuan, equivalent to a few fast-food meals. Prolonged idling may also cause premature battery aging, adding hundreds in maintenance costs. I recommend using it only briefly when necessary, such as short stops by the roadside, or opting for window ventilation to save fuel and enhance safety. Parking conditions matter too—while AC cools faster under scorching sun, ensure proper ventilation.

[MacElliana]

Idling with the air conditioning on for an hour consumes approximately 1.5 liters of diesel for a diesel vehicle, which I believe places a significant burden on the environment. Burning one liter of diesel emits about 2.7 kg of CO2, totaling around 4 kg per hour; prolonged idling accumulates carbon emissions, impacting the climate. Additionally, idling produces loud noise and tends to accumulate dust inside the vehicle. Alternative solutions include opening windows after parking and turning off the engine, or using a small fan; these are healthier options, avoiding poor air quality inside the car. To conserve energy, I try to avoid idling whenever possible.