Buying New Tires
To find out what kind and size of tires you need, look at the
CertificatiodTire label.
The tires installed
on your vehicle when it was new had a Tire Performance
Criteria Specification (TPC Spec) number on each tire’s sidewall. When you
get new tires, get ones with that same TPC Spec number. That way, your
vehicle will continue to have tires that are designed to give proper
endurance, handling, speed rating, traction, ride and other things during
normal service on your vehicle. If your tires have an all-season tread
design, the TPC number
will be followed by a “MS” (for mud and snow).
If you ever replace your tires with those not having a TPC Spec number,
make sure they
are the same size, load range, speed rating and construction
type (bias, bias-belted or radial)
as your original tires.
Uniform Tire Quality Grading
The following information relates to the system developed by the United
States National Highway Traffic Safety Administration which grades tires
by treadwear, traction and temperature performance. (This applies
only to
vehicles sold
in the United States.)
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 a 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.
6-66 ProCarManuals.com
