Tyre Expert asked 100 drivers in Newport, South Wales, whether they could tell what state their tyres were in. 46 of them couldn’t. They weren’t sure how to check their tread, and they didn’t know the depth at which a tyre stops being road legal.
That almost exactly matches the national picture. Research commissioned by Michelin UK, a survey of 2,000 drivers carried out in September 2026, found that only 53% know the legal minimum tread depth is 1.6mm. That leaves 47% who don’t, against 46% here, and nearly one in four drivers nationally don’t know how to check whether their tyres are road legal. Newport isn’t an outlier. Plenty of drivers here are relying on their annual MOT, or on luck, to tell them when a tyre has worn out.
The legal limit is 1.6mm
UK law sets the minimum tread depth for cars at 1.6mm. That depth has to run in a continuous band across the central three quarters of the tyre’s width, all the way around. A tyre can also be illegal whatever its tread depth if it has a cut longer than 25mm or 10% of its width, a lump or bulge in the sidewall, or cords showing through the rubber.
The penalty is up to £2,500 and three points on your licence for each illegal tyre. Four worn tyres could mean 12 points, which is enough for a driving ban.
Jack Spencer, owner of Tyre Expert, says the result of our survey didn’t surprise him.
“Most people I meet at the roadside when I’m fitting tyres in Newport have no idea what 1.6mm looks like, and that’s not their fault. Nobody shows you. The law says 1.6mm across the middle three quarters of the tyre, all the way round. If one section has worn below that, the whole tyre is illegal, even if the rest of it looks fine.”
How to check your own tyres
You don’t need any tools. Two quick checks will tell you most of what you need to know.
The 20p test. Put a 20p coin into the main grooves of the tread. If you can see the outer band of the coin, the tread could be at or below the legal limit and needs looking at. Repeat it in at least three places around the tyre, and do all four tyres, because they rarely wear evenly.
Tread wear indicators. Small raised bars sit at the bottom of the grooves, set at 1.6mm. If the tread surface is level with those bars, the tyre has reached the limit.
While you’re down there, look at the sidewalls. Bulges, cracks and cuts are easier to spot than worn tread and are just as serious.
“I tell everyone the same thing: don’t wait for 1.6mm,” Jack says. “That’s the legal minimum, not the safe point. Once you’re under 3mm your grip in the wet drops off quickly, and around Newport we get a lot of wet roads. If your tyre’s down to 2mm, start planning the replacement. Don’t wait for it to turn into a fine.”
Who’s giving the advice
Jack has run Tyre Expert based in Newport for over five years, and spent many more years fitting tyres before that. The business is RAC approved and has more than 400 five-star reviews on Google from drivers across South Wales and Bristol.
Tyre Expert is a mobile tyre fitting service based in Newport, covering the city along with Cardiff, Chepstow and Bristol. The business is based in Kelvedon Business Centre but brings the tyres to you, whether you’re on your driveway, at work or stuck at the side of the road. Response times can be as little as 30 minutes, and a fitting takes around 15 minutes.
“A lot of the people who ring me found out the hard way,” Jack says. “A blowout on the M4, a police stop, or an MOT failure they weren’t expecting. If they’d known how to check, most of those could have been a planned job on their drive.”
Get your tyres sorted in Newport
If you’ve checked your tyres and you’re still not sure, or the 20p test didn’t look good, call Tyre Expert on 07505 965373. Jack can come to you anywhere in Newport, day or night, and replace them on the spot. You can read what other drivers say on our reviews page, or see the areas we cover on our Newport mobile tyre fitting page.