I had a Renault Megane diesel that used to eat front tyres, about 8000 miles was the best although I switched to Kumhos that lasted better.

i have never failed to get 25K, usually more, from tyres over 50+ years of driving, and quite a few of my cars have been diesels (heavy front end). That may be an argument against buying cheap tyres - I usually buy mid-range.

I'd pay dearly to see a bicycle inner tube repaired from the inside..

When I bought a demo a few years ago, I had a slow puncture that turned out to be a poor repair and the tyre could not be repaired so the dealer who was decent did pay for a new tyre.

I'd base it on how worn the tyres are. I would say if the tyre that isn't punctured is 1mm worn or less (from whatever it's new tread depth should be for that model of tyre), then no.

2mm I'd say you're pushing it a bit - I'd probably change both, 3mm or more, absolutely change both.

You may also find that the rear tyres are better swapped to the fronts and the fronts (new) go on the rear, as a FWD car will benefit more from rear tyre stability gain from newer tyres when cornering in the wet.

I would check all the tyres for tread depth and uneven wear first before doing any of the above, just in case other changes need to be made - e.g. tracking/wheel alingment, etc. You might find one or more tyres has far more wear than others.

If you have Michelin Primacy tyres all around and they've been fine otherwise, then stay with a direct replacement. They are asymmetric tyres, I think, so don't mix and match asymmetric ones with directional tyres as the grip level will vary more than just by similar quality brands.

Edit: I forgot to ask - is the punctured tyre repairable with a plug, or is the damage severe enough - say to the sidewall, near the edge or a bad puncture generally so that it cannot be repaired? A plug repair would probably cost about £15.

Edited by Engineer Andy on 20/01/2022 at 19:11

They don't do plug repairs any more, there's a patch on the inside. Plugs are now deemed a temporary repair although I don't think they are actually illegal. A question of liability perhaps.

They use a mushroom plug which is both a plug and a patch inserted from inside the tyre and vulcanised with the appropriate adhesive. They come in several sizes.