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 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.
Honda Civic Service Manual. Drive Belt Removal and Installation (K24Z7)
118130
Removal
1.
Drive Belt
vnm
1.
Move the auto-tensioner (A) using the belt tension release tool
in the direction of the arrow to relieve tension from the drive
belt, then remove the drive belt.
...