What Impact Does Idling with Air Conditioning On Have on the Engine?

[ElleDella]

Keeping the car idling with the air conditioning on for extended periods can lead to wear and tear on vehicle components. The low idle speed of the engine results in poor cooling performance, failing to meet usage requirements. Additionally, using the air conditioning while the engine is idling can cause incomplete combustion of fuel (gas), producing a large amount of exhaust gases. Prolonged use of air conditioning in an enclosed space while idling can also lead to poisoning or suffocation. The hazards of idling with air conditioning on include: 1. Gasoline Combustion: Keeping the air conditioning on after parking, with the engine running only at idle speed, can lead to incomplete gasoline combustion. Unburned gasoline produces toxic substances such as carbon monoxide. If the car doors and windows remain tightly closed for an extended period, these exhaust gases can enter the enclosed cabin. Accumulation of these gases to a certain level can cause carbon monoxide poisoning. 2. Carbon Dioxide: Occupants inside the car exhale a significant amount of carbon dioxide. In hot summer weather, oxygen consumption inside the cabin is higher than in other seasons. As the oxygen level in the enclosed car gradually decreases, prolonged exposure can cause symptoms such as dizziness, nausea, and general weakness, which are clear signs of carbon monoxide poisoning.

[McAlivia]

I remember over all these years of driving, the impact of idling with the AC on is quite noticeable on the engine. Turning on the AC forces the engine to work harder to drive the compressor, causing fuel consumption to spike instantly. Normally, idling might consume less than 1 liter of fuel, but with the AC on, it can double, which hurts the wallet. More importantly, the engine temperature rises, making it prone to carbon buildup. Accumulated carbon deposits can cause the engine to shake and make starting difficult. My old car used to have this issue frequently, and later even changing the spark plugs became a hassle. My advice is not to idle with the AC on while parked—either turn it off or just use the fan for ventilation. In the summer heat, try parking in the shade to reduce AC usage time. Developing this habit not only saves fuel but also extends the engine's overhaul cycle, which is good for the car's lifespan. Short periods are fine, but be cautious if it exceeds half an hour.

[SanElaina]

From a money-saving perspective, idling with the AC on is simply burning cash. Calculations show that turning on the AC while idling can increase fuel consumption by over 20%. Parking for an hour can waste several extra liters of fuel, and these small amounts add up—monthly expenses can rise by a hundred or two. The engine bears a heavy load and wears out faster, potentially leading to soaring repair costs over time. A friend's car developed strange noises after two years of frequent idling with the AC on, resulting in unnecessary repair bills. My personal advice: turn off the AC if parked for more than five minutes, opting for natural airflow or a fan instead. If AC is a must, park in a cooler spot. This approach not only benefits your wallet but also extends your car's lifespan. Remember, a car is a tool—treat it well for long-term savings.

[McReid]

Idling with the air conditioning on isn't environmentally friendly. The engine runs more, emitting more exhaust pollution, which is harmful to the environment. Especially in cities, using air conditioning while idling worsens air pollution, and it's also prohibited by regulations. Personally, I make it a habit to turn off the air conditioning or just use the fan when parked. The impact may be minimal in the short term, but it accumulates and harms urban air quality.