Tyre Bulge

[Michaelw]

I have an AWD S running Michelin Pilot Sport 4s
225x35 20 on the front with about 6mm of tread
295x30 20 on the rear with about 5mm of tread

When I was cleaning it last week I noticed a bulge on the front nearside tyre about 35mm diameter and about 3mm high, presumably from hitting one of our many local potholes.

As it happens the car was booked in for a MOT this week. They have put a "Monitor and Repair if necessary" advisory on the MOT with a note "Tyre slightly damaged nearside front outer (sidewall) 5.2.3(d) (ii)

Is it OK to leave it? If so do I just keep an eye on it and see if it get worse or should I replace it? If I replace it I guess a new tyre would have about 7mm of tread , would this be OK with the other side having around 6mm?

Thanks

[Moss]

Personally, I'd replace.
The tread depth difference across the same axle is irrelevant.

[simpleR]

Replace. Tyres are the only thing keeping you on the road.
Last thing you need is it failing or deflating.

Surprised it wasn't a fail though.

[Deleted User 4828]

I'm surprised it was not a fail too. I agree replace. Hard cornering at speed will put extra strain of tyre. You will kick yourself if anything else were to happen.

If there are no marks on the tyre you may want Michelin to know, the batch that the tyre came from may have been a run of issues. Might be worth contacting the supplier from where the tyre was purchased. Report it to them if nothing else.

[Michaelw]

Thanks for your comments, it confirmed what I was thinking really , not worth the risk for the price of a tyre.