UK motorists will waste nearly £50 million of fuel this winter by leaving their cars to idle with the engine running in order to defrost them, a new study of regular drivers by Direct Line Car Insurance has discovered.

The study calculates that the fuel wasted equates to over 300 million road miles and would enable someone to drive an average sized car more than 13,0004 times around the world.

"This large amount of money going up in smoke is despite the average person taking only three minutes to defrost their car. With high fuel costs, even the smallest amount of waste can cost motorists dear," said Steve Price, head of Direct Line Car Insurance.

The study also found that five per cent of motorists admitted to letting their engine run for ten or more minutes before setting off on their journeys, making them responsible for £2.45 million of the total wasted on fuel.

"Wasting money on fuel is not the only thing motorists should be worried about. Of those questioned, 42 per cent admitted to leaving their cars unattended with the keys in the ignition, making them a perfect target for thieves and risking invalidating their insurance should the car be stolen," said Price.

"With fuel prices having risen more than 40 pence per litre since 2007, it makes more sense than ever to consider alternative methods of defrosting your car on icy days.

"It is really important that drivers never leave their cars unattended with the keys in the ignition under any circumstances, but particularly when defrosting their cars. Many of us are pressed for time in the mornings and so leaving your car to warm up while running back indoors to tie up some loose ends can seem like a clever use of our time. However, if a theft occurs under these circumstances policyholders may not be covered."

Direct Line’s de-icing tips

Prevention is better than cure. Where available, park your car in a garage overnight in order to drive away frost-free, and without any scraping, in the morning.

Alternatively, invest in a windscreen frost guard for around £6.99 or a car cover from £27.99 to £34.99, depending on the size of your vehicle.

Night-before aerosol sprays are available (£2.99) as another preventative measure. Spray your car’s windows when leaving it overnight and the ingredients prevent the ice from building on the glass.

For quick and easy ice removal, invest in a cheap de-icer aerosol, available for £1.99, coupled with a scraper for 99p, remembering to clear all the windows around the car. Failure to fully de-ice your windscreen could land you with a fine and even points on your licence.

If you do not want to purchase a car cover, an old blanket will do the trick. Lift the windscreen wipers up, stretch the blanket across the windscreen and secure it in place by closing it in the front passenger and driver doors, then lower the windscreen wipers. In the morning, remove the blanket to reveal an ice-free windscreen.

You should allow an extra ten minutes in the mornings to de-ice your car and sit in it while it is warming up, only setting off once all windows are clear and you have full visibility.