How does car air-conditioning affect fuel consumption?

Rising fuel costs, along with an increase in the cost of overall living, is a problem we are all facing. Understanding how your car uses its fuel, and what you can do to reduce the amount consumed, is a way to help offset the rise in costs.

Since the weather is due to heat up in the next couple of months – we can only hope! – it’ll be handy to know how to cool your car interior effectively, without using too much fuel. 

How much fuel does your air-con consume?

The compressor needs energy to run your vehicle’s air conditioning system and will use a small amount of fuel whenever the system is running. It could increase your fuel usage by as much as 10 per cent.

This inflation is more noticeable on short journeys; when you set off, the system has to work really hard to bring the internal temperature down. Once it’s down to a comfortable level, the airflow rate can be reduced, the temperature increased, or even turned off completely. Long journeys usually don’t require the air con to be blasting the whole way, hence why using your air-con on short journeys can cause more of an increase in fuel consumption.

How to save fuel:

• When you first start driving, try opening the windows for a couple of minutes if it’s warm. This will remove the majority of the hot air in the cabin so your air conditioning won’t have to work too hard.
• Remember, although driving with your windows open is fine (and can help reduce fuel consumption) at slow speeds, it is not advised to do the same when you’re driving faster. The drag caused by open windows could actually use additional fuel. 
• In terms of fuel usage, it’s obviously better to drive without the windows open or the air con on. But, on a hot day, this can make the cabin incredibly uncomfortable. 
• It’s crucial to have your car’s air conditioning system serviced regularly. Much like a boiler, your car’s air-con has to be maintained to prevent problems in the future, despite the fact that it seems to be working fine in the present. Your air-con system should be serviced every two years to ensure it is running efficiently and any lost refrigerant is replaced. The less efficient the system, the more fuel it will use.