Slow acceleration when air conditioning is on

As a car owner, you might have for once noticed a change in your car performance anytime you switch on the ac that you can’t help but wonder “why your car loses power when the ac is on”. This and every other car’s air-conditional intricacies will be addressed in this article.

Does AC damage the car engine

No, AC does not damage the car engine but can only slightly reduce the performance of the car.

Every functional part of a car whether it be the alternator, car radio, Pumps, the power steering, air conditioner, and every other component draws energy from the car engine to perform optimally.

So considering that they rely heavily on the car engine for good performance there are always competing interests, every bit of energy drawn from the car engine will affect the car functionality in one way or the other. These changes in car performance are so trivial, that most car owners don’t notice the changes.

Does AC affect engine power

Yes, AC affects your car engine power.

Just as earlier stated, various car components make use of energy from the car engine for effective performance. Take for instance, as you are driving on the highway your car acceleration consumes 20 horsepower of your car engine.

So as you are going about your cruising, the heat starts getting to you and you decided to switch on the AC, and your car AC gulps 2 horsepower. That is definitely an extra 1% load on your car engine. Therefore, in one way or the other your car engine is losing power, which will lead to a drop in its efficiency.

Does AC affect fuel consumption

Yes, AC affects fuel consumption.

A car AC is an additional load on the car engine, so just like most other activities like, turning on the car radio, or flipping on the car headlight, the AC also increases the car’s fuel consumption rate.

In fact, compared to some other supporting components, it accounts for the major reason why your monthly fuel expenditure increases.

According to a rough estimate, it is assumed that the car AC consumes close to 20% of total fuel. Although, the rate at which AC consumes fuel is highly dependent on some factors like, the size of the engine, the weather, the car model, and the state of the air conditioning.

Impact of air conditional load engine performance

The effect of air conditioning on the engine is easily noticeable through the car’s RPM. When you turn on your car AC, your car engine’s RPM will move in a clockwise direction, indicating an increase. This is a result of the activation of the compressor.

RPM is the standard measurement of a car’s functionality. It shows the rate at which the car crankshaft rotates during acceleration or deceleration.

Why does my car lose power with the AC on

That happens basically because your car is operating based on the power supplied by the engine. A car has less than 150 horsepower and this is distributed among every functioning accessory in a car once they are activated. The use of one component whether it is running or static causes the engine to lose power.

A typical car engine has a steady power to distribute, the car engine with the help of the clutch and belt system powers the AC compressor and this mounts pressure on the car engine in form of extra load.

So with pressure from the alternator charging the battery, coupled with that of the power steering pump, it is inevitable that the engine power will drastically drop. That is why your car loses power when you switch on your AC.

Why does my AC stop working when I accelerate

This may be as a result of a faulty vacuum check valve positioned right below the car bonnet. The check valve protects the AC door from losing a vacuum. If vacuum is lost, this may cause the AC door to defect towards the windscreen while the car is at top speed.

Another option is to check if your car compressor clutch is working perfectly. If your compressor clutch is intact, then it might probably be because your AC’s freon is insufficient. Freon is an AC coolant that helps transform evaporated internal heat from your car into cool air.

Is it ok to start your car with the AC on

No, it is not ok to start your car with the AC on.

Although this depends largely on the car model you drive. So it is not particularly bad but it is recommended that you off your AC before starting your car.

Leaving your car in the parking lot in scorching hot summer weather can heat up the interior of your car, so it may become necessary to switch on the AC for some minutes before you actually hop in for a smooth ride home.

When you start your car while the AC is on, what happens is that you will be starting your car with a more electrical load than it is required and this could affect your car ignition. Although this depends on the design of the car.

If your car is designed so that the impact of the extra load is felt directly by the car ignition, then you are likely to wear out your car ignition switch contact earlier than expected. But if your car is designed in such a way that the impact is felt by an actuator, then no noticeable damage can occur.

Do I need to turn off AC before turning off the car

No, you do not have to turn off your AC before turning off the car. Although I would strongly recommend that you deactivate every electrical system because if any is left running after you switch off your car, they start to draw energy from the car battery and you might have a little problem starting your car for the next ride.

How to reduce AC load on the engine

The following will help reduce loads on your car engine.

  1. Adopt sophisticated window glazing or parked car ventilation.
  2. Minimise the inflow of air brought in from outside for ventilation.
  3. Turn off any car accessories that are not in use.

You may also like

2021 casement/window air conditioners buyer’s guide