Does idling the engine with AC on for half an hour damage the car?
4 Answers
There will be some impact. Idling consumes gasoline, which is no different from being stuck in traffic. However, the three-way catalytic converter does not work fully, polluting the air. Moreover, prolonged idling leads to incomplete combustion in the engine, resulting in more carbon deposits. If the temperature is low, even more deposits will form. Therefore, prolonged idling to warm up the engine does not effectively protect it but rather reduces its health. Below is additional information: The purpose of idling in place: Idling to warm up the engine means starting the engine in neutral to heat it up. This method mainly warms up the engine's lubrication and temperature. Regarding lubrication, about 30 seconds is generally sufficient.
I often get stuck in traffic while commuting to work in the city, and sometimes when it's hot, I idle the car with the AC on for half an hour. I've asked a few mechanic friends, and they said doing this occasionally doesn't have much impact on the car. After all, the AC compressor is driven by the engine, and idling just burns a bit more fuel to maintain power. However, if done frequently over time, the accumulated carbon deposits could affect engine efficiency and lifespan—kind of like how eating junk food every day isn't great for health. So, I usually limit it to under half an hour, like when waiting to pick up my kid from school or taking a short break on the roadside. If it's going to be longer, I just turn off the engine and roll down the windows for some breeze. Modern cars are designed to be pretty sturdy, so as long as it's not too frequent, it's fine.
I'm a car enthusiast, and idling with the AC on for half an hour isn't a big issue—the engine can handle the load. However, it's important to note that low engine temperature during idling can lead to carbon buildup, and prolonged idling can increase fuel consumption and emissions. To counter this, I take my car for a few high-speed runs each week to clear it out. Modern cars come with fuel-saving systems, so half an hour of idling consumes about 0.2 to 0.4 liters of fuel, equivalent to driving an extra kilometer. Cost-wise, it's not too significant. From an environmental standpoint, concentrated exhaust emissions are bad for air quality, so I prioritize parking in shaded areas and turning off the engine when possible.
Does idling with AC on for half an hour damage the car? From my driving experience, it's fine for short periods. The engine is designed to handle AC load, and half an hour won't harm critical components. The only downside might be slightly increased fuel consumption, with the fuel gauge dropping a bit faster, but it's much better than suffering heatstroke. Just don't make it a regular habit, especially for older vehicles which are more prone to issues.
