Treadwear
The treadwear grade is a comparative rating based on the wear rate of the tire when tested under controlled conditions on a specified government test course. For example, a tire graded 150 would wear one and one-half (1 1/2) times as well on the government course as a tire graded 100. The relative performance of tires depends upon 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.
See also:
Oil viscosity
The engine oil viscosity or thickness changes
with temperature. Because of this, it is important
to select the engine oil viscosity based on the
temperatures at which the vehicle will be operated
...
Checking tire pressure
1. Remove the valve stem cap from the
tire.
2. Press the pressure gauge squarely
onto the valve stem. Do not press too
hard or force the valve stem sideways,
or air will escape. If the hissing
...
Selecting the correct oil
It is essential to choose the correct grade,
quality, and viscosity engine oil to ensure
satisfactory engine life and performance, see
“Capacities and recommended fuel/lubricants”
earlier ...