Passenger-type tire with 1.6mm wear bars in the tread. A tire’s tread depth is critical on rain wet pavement and snow. The depth of the tread is the way a tire pushes water from under the tire and channels it out so the tread can contact the pavement for traction. A tire with very little tread has a greater chance of hydroplaning, which may cause the driver to lose control of the vehicle. Only on dry pavement is less tread better for traction.
Passenger Car Tires – Tires worn past the tread life – New passenger vehicle tires generally have 10/32 (7.9 mm) to 11/32 inch (8.7 mm) tread depth. The depth is dependent upon the type of tread pattern and the utility purpose of the tire. The Uniform Tire Quality Grading (UTQG) rating is an indicator as to how many miles a tire should obtain before it reaches the wear bars. The UTQG rating should be used to compare one tire with another from the same manufacturer. Brand “A” may rate a tire that will not give the same mileage as Brand “B”. UTQG is only an indicator, however, not a regulation.