A simple 20p hack can save drivers from a £2,500 fine and a driving ban

Drivers caught with worn tyres beneath the legal limit of 1.6mm face a fine of up to £2,500 and up to 12 penalty points - enough to have their license taken away. Although the penalty could be far more severe for new drivers – two worn tyres is the equivalent of six points, enough to lose their permit.

But there is an easy way to check your depth, by using the border of a 20p coin which is slightly larger than the limit, making it the ideal tool to help you avoid the big bill.

Yet 38 per cent of motorists didn't know about the trick, rising to 59 per cent among younger drivers – who run the risk of losing their license. Almost a third (30 per cent) are unaware of the hefty fine they could face if caught driving with illegal tyres.

However, 48 per cent said they don’t have coins on them or in their car – so aren’t able to do the quick check.

A poll of 2,000 motorists, released during Tyre Safety Month, reveals 60 per cent do it only every few months or less whereas 23 per cent don’t do it at all because they assume they'll be fine.

Halfords has worked with comedian Judi Love to urge Brits to keep a 20p coin in their car as a safety measure and released a limited number of 20p key chains.

To help motorists do the test, Judi presented an informative video showing drivers how to check their tread using the coin.

The comedian said: “It's a simple check that takes seconds but could save you a pretty penny. Just by carrying a 20p coin in the car and checking it every now and again, or before long drives, you can help make sure your car tyres are not only legal but also safe.

“I am not someone you’d call car-savvy, but even I can do that. Or I’ll get my daughter to do it for me. It takes less than 30 seconds to check all four tyres and is definitely worthwhile when you consider the safety implications, let alone the cost of the fine or even losing your license.”

More than a quarter (27 per cent) admitted they aren't confident they could tell if their tyres were no longer road legal, and 64 per cent didn't know about the 1.6mm legal tread limit.

As winter approaches, the OnePoll.com study found 61 per cent get their car winter-ready simply by putting de-icer or an ice scraper in the vehicle.

Exactly half (50 per cent) check their tyre pressure and 39 per cent check the tread depth. Meanwhile, just 21 per cent will book their car into a garage for a check-up.

It was also found 55 per cent have broken down at least once, with the average motorist left stranded for 76 minutes.

Karen Bellairs, chief customer officer at Halfords added: “Getting winter-ready is about more than putting an ice scraper in the car. When roads are wet or icy, the condition of your tyres matters to the safety of every journey.

“You don’t have to be a car expert to check them. A 20p piece can help you spot when your tyre tread may be too low, giving you a chance to act before your next journey. And if you’re unsure what you’re looking for, our experts are here to help.”