A new investigation by Halfords and Cardiff University’s Centre for Automotive Research has found that more than 1.2 million vehicles are sold each year with tyres that may not even last until their next MOT.
The study examined nearly 500 secondhand cars across 100 UK locations, uncovering widespread issues with tyre condition and highlighting serious gaps in consumer protection and regulation.
According to the findings, around one in six used cars (16%) were being sold with 3.6mm of tread or less, a level Cardiff University’s Professor Peter Wells described as “potentially dangerous.”
With the average car using around 2mm of tread per year, these vehicles could easily fall below the legal minimum before their next MOT.
Many were already close: one in twelve (8%) cars had tyres with 3mm of tread or less, and several were being sold at or below the legal limit of 1.6mm, including vehicles with 12-month MOT certificates.
Professor Wells warned the situation is “an accident waiting to happen.” His analysis showed that cars with tyres at 1.6mm take 75 metres longer to stop from 70mph in wet conditions, the difference between stopping safely or crashing at around 46mph.
Legal but unsafe
Under current UK law, it is legal to sell a car with tyres at the minimum 1.6mm tread depth as long as it holds a valid MOT.
But just 0.01mm of wear beyond that would make the tyre illegal — meaning some cars could become unlawful to drive within 30 miles of leaving the forecourt.
“It’s a loophole that puts lives at risk,” said Adam Pay, Managing Director at Halfords Autocentres.
“Most motorists don’t check tyres between MOTs and expect the car they buy to be safe for the next year. The fact it’s legal to sell a car that could be illegal days later lacks common sense and could cost lives. The law needs an urgent rethink.”
The research uncovered worrying examples from across the market, including main dealers selling vehicles with dangerously worn tyres.
One £15,000 used car was found with just 1.6mm of tread, barely legal, while another £8,000 car had tyres at 1.55mm and visible damage.
The consumer side tells the same story. Halfords’ survey found 81% of drivers believe it should be a legal requirement that all used cars are sold with tyres that will last until their next MOT.
Of those who bought a used car in the past year, more than half (53%) said they’ve already had to replace at least one tyre. Four in ten said they’d feel “let down” if they bought a car with less than 3mm of tread, while over a third said they’d feel “put in danger.”
Why it Matters
When cars are sold with tyres already near the legal limit, it’s often your workshop that discovers the problem first. That creates both a responsibility and an opportunity:
– Protect your customers: A quick tyre check could prevent a serious accident.
– Build trust and loyalty: Honest, safety-first advice sets independents apart from quick-turn dealers.
– Drive repeat business: Educating motorists about tread depth, braking distance and tyre age encourages regular visits and proactive maintenance.
– Champion professionalism: By raising standards locally, garages reinforce the industry’s commitment to safety and transparency.
Professor Wells and Halfords are calling for a review of the UK’s tyre tread laws, suggesting a minimum of 3.6mm or even 4mm at point of sale.
“Tyres are one of the most safety-critical components on any vehicle,” said Wells. “Once they reach 3mm, performance starts to deteriorate significantly, especially in the wet. The difference between 8mm and 1.6mm isn’t just numbers on a gauge; it’s metres on the road and lives at stake.”
Stuart Lovatt, Chair of TyreSafe, praised the study for shining a light on a neglected safety issue: “This is the most detailed investigation we’ve seen into tyre condition on used cars.
“It shows just how many are being sold with sub-standard tyres. Buyers need to be vigilant, and dealers must take greater responsibility for vehicle safety.”
