A study of a fleet of 730 vehicles at a site in Berkshire found that 26% had at least one tyre with a tread depth of 2mm or less.
The figure represents 321 tyres on 191 vehicles and although the current legal limit is 1.6mm, experts say a tyre with 2mm of tread depth would only need to travel a further 250 to 500 miles to reach the minimum level.
A further 30 vehicles were also found to have tyre problems including worn edges, cracking, sidewall damage and one with a screw in the tread.
The study was carried out by Lloyds TSB autolease in conjunction with its tyre partner Hi-Q and tyre manufacturer Goodyear Dunlop.
Terry Birch, technical services team manager at Lloyds TSB autolease said: ‘Whilst the minimum legal tread for tyres is 1.6mm, we offer our customers new tyres when they reach 2mm to ensure the highest levels of safety and to allow them flexibility in getting their tyres replaced.’
Company bosses say that if the same results were true for private vehicles then nearly seven million vehicles are running on potentially dangerous tyres.
Birch added: ‘Good tyres are absolutely essential for safe driving. Even the smallest change in tyre pressure can impact negatively on the road worthiness of a vehicle and in extreme cases, drivers can face fines and penalty points if the vehicle they are driving is found to have defective tyres. What’s more, how the car is driven will impact hugely on how regular checks need to be.
‘And it’s not just an issue of maintaining safety on the roads – under-inflated tyres will increase fuel consumption and ultimately fuel bills. Our advice to fleet managers and drivers is to ensure that tyre checks are carried out on a regular basis to prevent tyre defects and high fuel consumption costs.’