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 Owners Manual. Airbag Care
You do not need to, and should not, perform any maintenance on or replace any
airbag system components yourself. However, you should have your vehicle
inspected by a dealer in the following situations:
When the airbags have deployed
If an airbag has inflated, the control unit and other related p ...