Why does a sedan experience insufficient power when the air conditioning is on?

[LeWilliam]

It is normal for a car to experience insufficient power after turning on the air conditioning, and this phenomenon becomes more noticeable with older vehicles. This happens because the car's air conditioning is powered by the engine, and the air conditioning compressor draws its power from the engine. As a result, some power is consumed during the operation of the air conditioning, leading to a sensation of sluggish acceleration and insufficient power. The power consumption of a car's air conditioning compressor is around 25 kW. Nowadays, mainstream naturally aspirated engines can achieve a maximum power output of over 80 kW. However, a car's engine may only reach its maximum power output at around 5,000 RPM, which means that at lower engine speeds, the power output might only be around 20 to 30 kW. In this scenario, the air conditioning consumes about 20% of the engine's power, which is a significant proportion and can create substantial resistance for the engine.