Does air con use petrol?

28 August 2020

The short answer is yes - air con does in fact increase your fuel consumption and use more petrol. Research suggests that by using your air conditioning in your vehicle, you can increase your fuel consumption by around 8-10%.

However, it's important to note that driving with your windows open can also reduce your fuel efficiency. Having the windows open while driving, especially at high speeds, can create a 'drag' for your vehicle - which means the engine must work harder to pull the vehicle. As the open window creates a type of resistance, this then, in turn, increases the amount of petrol used.

Air conditioning vs open windows

So how do you know which is more economical and environmentally friendly - opening your windows, or using your air conditioning?

It is mostly dependent on the speed you're travelling as to whether you should use your air conditioning or open your windows. For example:

• If you're travelling at speeds below 50mph - in this case, it's more economical to open your windows. Travelling at lower speeds is less likely to create the 'drag' effect which increases your fuel consumption. Whereas by using air conditioning at this speed, it would actually create extra demand on your engine.
• If you're travelling at speeds above 50mph - in this case, it's better to use the air conditioning system, as having the windows open at this speed can incur the 'drag' effect that will reduce fuel efficiency.

What will improve fuel consumption?

As well as resisting using your air conditioning and driving with the window open, there are other things you could do which will improve fuel efficiency.

• Driving style - how you drive your vehicle will naturally have an impact on your fuel consumption, for example, if you are using harsh acceleration and you're frequently changing gears, this is likely to use more petrol.
• Heavy load - does your vehicle have unnecessary objects in the boot? Having a heavy load, even if this means having more passengers than usual, can affect your fuel consumption - as this too creates the drag effect.
• Tyre pressure - are your tyres inflated to the correct pressure? If not, this could have a detrimental affect on your fuel efficiency - as it can create a larger surface area if your tyre is underinflated, which means there will be more drag on the wheel.

Now you're clued up on what will improve fuel consumption, and how using air conditioning affects your fuel efficiency, browse our range of air conditioning services here at Setyres. For more information, get in touch with a member of our team or locate your nearest branch.