Why does the car lose power when the air conditioning is on?

[DeAmir]

When the air conditioning is turned on, the compressor starts, and the engine has to drive the compressor to work, which inevitably consumes power, equivalent to a reduction in the car's driving power, making the car seem sluggish. This is quite normal. Introduction to Car Air Conditioning: Car air conditioning consists of a compressor, condenser, throttle element, evaporator, fan, and necessary control components, used to regulate the temperature and humidity inside the car, providing a comfortable environment for the driver. How Air Conditioning Works: When the compressor is working, it sucks in low-temperature, low-pressure gaseous refrigerant from the evaporator. After compression, the temperature and pressure of the refrigerant increase, and it is sent to the condenser. Inside the condenser, the high-temperature, high-pressure gaseous refrigerant transfers heat to the outside air passing through the condenser and liquefies, turning into a liquid. The liquid refrigerant flows through the throttle device, where its temperature and pressure decrease, and it enters the evaporator. Inside the evaporator, the low-temperature, low-pressure liquid refrigerant absorbs heat from the inside air passing through the evaporator and evaporates, turning into a gas. The gas is then sucked back into the compressor for the next cycle.

[LaBrayden]

I've been driving for over a decade and often experience a noticeable loss of power when the air conditioning is on, especially during acceleration or climbing hills. This is mainly because the AC compressor consumes part of the engine's power to operate, working in conjunction with the generator via a belt. If your car has a small displacement or is an older model with limited power, running the AC can be particularly taxing, potentially reducing horsepower by about 10%. The burden increases when the temperature is set lower or the fan speed is higher, and if the engine isn't well-maintained—such as having carbon buildup or a dirty air filter—the situation worsens. I find this issue most annoying during city driving, where fuel consumption also rises. It's advisable to ventilate the car by opening windows before turning on the AC or to regularly check the AC filter and compressor efficiency. On long trips, slightly raising the AC temperature can help alleviate the problem. Don't overlook these issues, as prolonged neglect can lead to worse vehicle condition over time.

[Leroy]

As a car enthusiast, I must say that lack of power when the AC is on is a common phenomenon, mainly due to the compressor consuming engine power. When the AC button is pressed, the compressor starts and draws power through the belt drive, resulting in reduced engine output. This is more noticeable in low-displacement vehicles, especially under heavy summer loads, when the car may feel sluggish or experience unstable RPM. Other factors, such as refrigerant leaks, can increase the compressor's workload and accelerate power loss. In daily driving, I've tried different methods to mitigate this: maintaining engine health with regular oil changes and throttle body cleaning can improve efficiency. Timely replacement of the AC filter is also crucial. If the problem is severe, checking the belt or upgrading to a high-efficiency compressor might help. Remember, using the AC increases fuel consumption by about 10%, so smart practices like opening the windows for ventilation before turning on the AC can save some power.

[McJordan]

When I first started driving, I bought a used car with a small engine. Every time I turned on the AC, the car felt particularly sluggish, accelerating as slowly as an ox pulling a cart. This is related to the AC compressor drawing power from the engine—when the engine is under more load, it naturally loses strength. It’s common to struggle with acceleration at traffic lights or when climbing hills. If the engine isn’t well-maintained, such as having carbon buildup or a clogged air filter, the situation worsens. During hot summers, I’ve tried lowering the AC settings or turning off recirculation to reduce the load. Developing good habits like turning off the AC before shutting down the engine can save some fuel. Running the AC typically increases fuel consumption by about 5-10%, so pay attention to these changes and prioritize maintenance.