Checking your legal tyre tread depth is one of the most important checks you can make on your taxi.
Having worn tyres means the only contact patch between you and the road is past its best. You are almost certainly putting yourself and your customers at a higher risk when driving.
If the safety risks don’t hit home, maybe the risk of a £2,500 fine and three penalty points for a worn tyre will? That’s per tyre, too. If all four tyres are worn below the legal limit, you could potentially lose your licence and face a £10,000 fine.
What is the legal tyre tread depth? The legal tyre tread depth for cars in the UK and Europe is 1.6mm across the central three-quarters of the tyre, according to law. The tread must meet this minimum requirement across its complete circumference.
What is the expert-recommended minimum tyre tread depth? According to the RAC tyre and safety experts believe the 1.6mm legal minimum is insufficient to guarantee safety – most recommend a minimum tread depth of 3mm for tyre replacement. Tests by UK technical organisation MIRA found that, once tyres are below 3mm, stopping distances increase dramatically. The difference in wet braking distance between a tyre worn to 3mm and one worn to 1.6mm can be as much as 44%. Worn tyres are particularly dangerous in the wet because a tyre’s tread helps disperse water away from the contact patch between tyre and road. If there’s less tread depth, less water can be shifted, increasing the risk of aquaplaning and losing grip. In heavy rain, each tyre can shift one gallon of water every second, illustrating just how hard tyres work. Simply put, deeper tread means they can work better, improving grip.
How to check tyre tread depth – the 20p test The 20p test is a simple, quick and easy way of checking the tyre tread of your car's wheels. Just take a 20p coin and insert it into the tread grooves on the tyre. If you can't see the outer band on the coin, your tyres are above the legal limit. However, if you can see the band and that section of the coin is still visible, your tyres could be unsafe and require professional inspection by a mechanic. The RAC suggest drivers conduct the 20p test around every two weeks and before long journeys.