Roof racks, luggage boxes, golf clubs and other items left in the boot all increase the car’s weight and fuel consumption, the AA is warning.
Tim Shallcross, head of technical policy for AA Road Services, said: ‘Tyres should be inflated as directed by the car manual. Under-inflated tyres increase rolling resistance and therefore fuel used, which can reduce economy by a couple of miles per gallon.
‘Using the air conditioning constantly at 30mph adds as much as 11p every 10 miles to the running costs of a car. Even at 70mph, using the air conditioning adds 7p every 10 miles.’
Another tip is to regularly clean the insides of the car windows. This will reduce the need to use the car’s demisters and blowers and will help decrease fuel consumption.