Treadwear
The treadwear grade is a comparative rating based on the wear rate of the tire when tested under controlled conditions on a specified U.S. government course. For example, a tire graded 150 would wear one and one-half times as well on the government test track as a tire graded 100.
The relative performance of tires depends upon the actual conditions of their use, however, and may depart significantly from the norm, due to variations in driving habits, service practices and differences in road characteristics and climate conditions.
See also:
Cleaning the wheels
WARNING
Do not use power washers with circular-jet
nozzles (dirt grinders) to clean your vehicle, in
particular the tires. You could otherwise
damage the tires and cause an accident. ...
Maximum permissible gross vehicle
weight rating
■ Specification for maximum gross vehicle
weight 1 is listed in the Tire and Loading
Information placard: "The combined weight
of occupants and cargo should never
exceed XXX kilograms ...