Originally Posted by andyk500
My sottozero 19" run flats have now covered 27,000 miles and the backs still have 3 mm on them with 5+ mm on the front, so no problems running them all year round.
Ooops, wrong time of year to be down to 3mm with a winter tyre, so you need some new ones for the winter.... Need at least 4mm tread for winter tyres to do their job during winter months.
I know some folks run winters tyres out during the summer, once past their best winter use.