I always keep an eye on the tread depth, which was fine.

But the car failed MOT because on outside edge of both front tyres (where base meets side wall) its worn down to the structural threads, I.e. absolutely ALL rubber gone.!!

Aren't those two statements contradictory?

I measure the tread depth of my tyres every 5,000 miles, at 6 different points across the width of each tyre - the results are then put in a spreadsheet so I can analyse the rate of wear and make an informed guess on tyre pressure and/or the need for a full 12-axis laser alignment.

Dont seem contradictory to me.

There is, pretty much inevitably, going to be a point where the tread ends and the sidewall begins, which would likely be exempt even from your intense tread surveillance programme, and very likely from the more relaxed (and ...er...normal?) regime implied by "keep an eye on the tread"

OP, maybe investigate the disappearance of chalk marks across the width of the tyre and down the sidewall during cornering manouvres at different tyre pressures.

And maybe dont buy another one.

Edited by edlithgow on 12/12/2024 at 03:52

Good question. If not, | think it's likely that the inward leaning front wheel, combined with power steering and frequent manoeuvring in a heavy car, could account for the tyre damage.

I'm surprised it wasn't noticed on the outside however. I had a Scorpio about 25 years ago, when the Highways dept added about a mile of very ugly home made speed cushions to my daily route. I got into the habit of straddling them. AT the MoT, the inside edges on the fronts were shredded wire wire hanging out. Very hard to see under those cavernous arches.