05-27-2017, 03:17 AM
The safe level of tire tread remaining has more to do with road conditions and tire design than a set height. You couldn't drive here in the winter with either 1.6 or 3mm safely. However, in SoCal either would be fine and you could go down to 1mm in the dry summer. Depending on the tread design and compound you could easily get adequate grip in normal conditions with almost no tread remaining.