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.
Tires
...
M+S tires
WARNING
M+S tires with a tire tread depth of less than
1/6 in (4 mm) are not suitable for use in winter
and do not provide sufficient traction. There
is a risk of an accident.
M+S tires with a ...
Problems with the windshield wipers
The windshield wipers are obstructed
Leaves or snow, for example, may be
obstructing the windshield wiper movement.
The wiper motor has been deactivated.
► For safety reasons, you should ...