How Much Fuel Does Using AC in Traffic Consume?
2 Answers
It depends on the temperature setting of the AC and the duration of its use. The lower the temperature setting and the longer the AC is on, the more fuel it consumes. Impact of AC Fan Speed on Fuel Consumption: Using the AC consumes more fuel mainly because the AC compressor requires significant power to operate. However, the variation in fan speed has minimal impact on power demand. Therefore, within a certain speed range or wind resistance, using the AC increases fuel consumption, while turning it off saves fuel. The effect of AC fan speed on fuel consumption is negligible, including when only using the heater in winter. Impact of AC Temperature on Fuel Consumption: When it's too hot and the AC is necessary, avoid setting it to the coldest temperature—moderate settings are sufficient. The most comfortable temperature range for humans is 20-25°C. Above 28°C, it feels uncomfortably hot, and below 14°C, it feels too cold.
When I'm stuck in city traffic, I often turn on the air conditioning, which does significantly increase fuel consumption. Generally speaking, during traffic jams, the engine is idling at very low efficiency. When the AC is on, the engine has to additionally power the compressor and fan, increasing the load and causing fuel consumption to be 10% to 20% higher than normal driving. If it's very hot, keeping the windows closed and the AC on prevents the cabin temperature from skyrocketing, making occupants more comfortable. Safe driving is more important, so I rarely force myself to save fuel at all costs. My car is an ordinary family sedan – being stuck for half an hour with the AC on can increase fuel consumption by one or two notches compared to normal conditions. Some models like small-displacement vehicles are affected even more, but trying to maintain stable AC operation without frequent switching can slightly help control it. Getting stuck multiple times in summer noticeably drives up fuel costs. Sometimes I try briefly opening windows for ventilation, but when it's too hot this barely helps, so I still rely on AC for peace of mind.
