SHOULD OUR TYRES BE CRACKING AT 15,000 MILES?

QWe bought a new Audi A4 in December 2021, and it’s just had its second service at 15,000 miles, during which it was noted that all four tyres (Bridgestone 245/40R18) are cracking within the tread. The dealer recommended replacement, at about £660. I realise tyres are not covered by the warranty, but do you think such cracking is normal and reasonable? There is plenty of tread left, so I was not planning to replace them yet. Furthermore,

will the cracking fail the MOT, due next year?

– TP

AWith your email, you sent me the video taken by the technician who carried out the service, which showed the cracks. These are towards the outer edge of each tyre, within the tread grooves, and around the entire circumference. Some cracks are so severe as to be showing the tyre cords.

This is an unusual place for tyres to crack. Age-related, cracks usually start to appear in the sidewall, rather than within the tread grooves. So it’s hard to say for sure what’s caused them, but I’d be disinclined to think it’s a manufacturing defect.

It is possible that the cracking could have been caused by under- or over-inflation. Were the tyres run with too little air in them, the excess heat built up could prove detrimental, ageing them prematurely and causing them to lose elasticity. With too much air, the excessive pressure could cause the rubber to be stressed to the point of breaking.

It’s also possible that extremes of temperature, exposure to the sun’s UV rays, repeated driving over speed humps at too high a speed, or some sort of chemical contaminant that you may have inadvertently driven through could have caused the rubber to dry.

Either way, as you say, tyres are not covered under a guarantee, and given the potential reasons for the tyres’ failure, you’ll have a tough job convincing Bridgestone or Audi that you have a legitimate case for a goodwill claim.

In any case, I would strongly suggest replacing the tyres as soon as possible, irrespective of whether they’ll fail the MOT. When tyres are cracking in this way, their structure is irreversibly compromised, and you could be at risk of delamination at higher speeds.

iTread carefully: tyres that are damaged for any reason should be replaced at once