What Changes Occur in Vehicle Power When the Air Conditioning is Turned On?
2 Answers
When the air conditioning is turned on in a car, the vehicle's power will decrease, and this effect is more noticeable in engines with smaller power outputs. This is because all the energy required for the car's air conditioning system is supplied by the engine. Whether it's driving the compressor, powering the motor, or drawing electricity from the battery, the air conditioning system consumes a portion of the engine's power. When the car is operating at low power, some of the power originally intended for driving is diverted to supply the air conditioning, inevitably leading to a reduction in driving power. The principle is as follows: The operation of the car's air conditioning system must draw energy from the engine. For example, the air conditioning compressor is connected to the engine's power gear via a belt and electromagnetic clutch, requiring the engine to drive it; the blower and fan systems obtain electricity through the motor to maintain operation; other low-power electrical devices rely on the battery's stored power. Since a car's power output increases linearly, the impact of the air conditioning on power varies at different stages.
Turning on the A/C noticeably affects the car's power. Every time I press the A/C button, I can feel the engine working harder, especially when climbing hills or accelerating in small-displacement vehicles. This happens because the air conditioning compressor is directly driven by the engine, consuming 10%-15% of its power. Once, when driving my friend's 1.6L manual car, it easily climbed a hill without A/C, but with A/C on, the throttle felt heavier, requiring the RPM to reach 3000 just to barely make it. In city driving, the difference isn't as obvious, but in summer with a full load and max cooling, the car noticeably struggles during acceleration. To minimize the impact, you can turn off the A/C before accelerating on highways or briefly switch off the AC before overtaking to regain some power. Experienced drivers know to use the A/C wisely—ensuring comfort without overburdening the engine.
