Tire Tread Wear

Tread Wear. Tread wear grade is a comparison rating based on

the wear rate of a standardized tire, tested under carefully con-

trolled conditions, which is assigned a value of 100.

A tire rated 200 should have a useful life twice as long as the

standard tires.

Note : The standard tire has a rating for tread wear of 100. This

vehicle has generally been accepted to mean a useful life of

20,000 miles of Normal driving. Therefore, a tire rated at 200

could be expected to last 40,000 miles.

The tread wear life of any tire is affected by driving habits ( fast

stops, starts and cornering will decrease tread life ), tire rotation

or lack of tire rotations , inflation, wheel alignment, road surfaces                       and climate conditions.

Traction.Traction performance is rated by the letters AA, A, B and C,

with AA being the best.

Note : The traction rating is for Wet Braking distances only! It does

not include cornering traction or Dry Braking performance. The

traction rating is only one of many factors that affect wet braking

traction, including air inflation, tread depth, vehicle speed and

brake performances.

Temperature Resistance. Temperature resistance is rated by the letters

A, B and C, with A being the best rating. Tires generate heat while ro-

tating and flexing during normal driving conditions. A certain amount                of heat buildup is desirable because tires produce their highest coeffic-

ent of traction at normal operating temperatures. For example, race

car drivers frequently swerve their cars left and right during pace laps,

causing increased friction between the tire and the road surfaces, which

warms their tires to operating temperature. However; if temperatures

rise too much, a tire can start to come apart – the oils and rubber in

the tire starts to become a liquid ! Grade C is the minimum level that all

Automotive Principles Technology – James Halderman

https://www.sokule.com/blog/cbarkwell