Does Car Air Con Use Up Fuel?

It’s difficult in the summertime to decide whether to simply open your car window or turn on the reliable air con system for that refreshing shot of cool air on a sunny day, but which is better for fuel consumption?

How Much Fuel Is Used By Air Con?

This is determined by many factors. From the size of your engine to how recently your car has been serviced, could have an impact on the amount of fuel you use by turning on your air con. Having the AC on could reduce 5%-10% of your mpg (miles per gallon), especially if you have it on every time you drive.

Air Conditioning Settings

Depending on the amount of air you want to pump out, the temperature it’s on and the speed it’s set to, you could be wasting fuel by utilising your air con system. Having the AC on uses energy that’s supplied to it by the alternator. This energy comes from the engine which uses the fuel in your petrol tank. The faster the air comes out, the more fuel you’ll be using.

Size, Power and Temperature of Your Engine

Your vehicle’s engine drives the pump that expels conditioned air, whilst simultaneously supplying the rest of the car with energy where required. If the engine is large enough and adequately powerful enough to deal with this, your fuel consumption will be lower with the AC on. The bigger the engine, the less fuel you’ll use when you have the AC on.

It can also depend on how hot or cold your engine is when you turn the air conditioning on. A warmed up engine that is at an optimum temperature generally performs a lot better than a cooler one.  Only use it when you need to (when it’s too hot or too cold outside).

Has the Car Been Serviced Recently?

An AC system that’s been serviced recently will be in good condition and so will be more efficient than one that hasn’t been checked over by a professional. If your AC is unable to cool your cabin effectively, it most likely needs to be recharged by a professional, who will use specialist tools to replace the refrigerant that has escaped from the system.

air conditioning

Is It Better To Open The Window Instead Of Putting The AC On?

This is an age-old debate. But General Motors and SAE (Society of Automotive Engineers) worked together to try and answer this ever popular question. They concluded that in fact, it would be better to have your windows down.

Having conducted tests in a wind tunnel, it was found that having the windows down used less fuel than having the AC on, regardless of how fast you’re travelling. However, having the windows down at high speeds or whilst driving along roads that have a rough, rocky or loose terrain could be dangerous, so we recommend you drive with the windows shut and the AC on in those circumstances.

FM Mechanical and our specialist team of technicians are fully versed in servicing a wealth of different air conditioning brands. We repair, install and service an extremely wide range of air conditioners. We believe our customers should never settle for anything less than the very best high-quality, energy-efficient and extremely durable air conditioning systems. For more information about the products we sell or the services we offer, don’t hesitate to contact us today – we’re more than happy to help.