When It Is Time for New Tires
One way to tell when it’s
time for new tires is to
check the treadwear
indicators, which will
appear when your tires
have only 1/16 inch
(1.6 mm) or less of tread
commercial truck tires may
not have treadwear
You need a new tire if any of the following statements
You can see the indicators at three or more places
around the tire.
You can see cord or fabric showing through the
The tread or sidewall is cracked, cut or snagged
deep enough to show cord or fabric.
The tire has a bump, bulge or split.
The tire has a puncture, cut or other damage that
can’t be repaired well because of the size or
location of the damage.
Buying New Tires
To ﬁnd out what kind and size of tires your vehicle
needs, look at the Certiﬁcation/Tire label or the Tire and
Loading Information label. See Loading Your Vehicle
on page 4-32, for examples of these labels and
where they are located on your vehicle.
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,
GM recommends that you get tires with that same TPC
Spec number. That way your vehicle will continue to have
tires that are designed to give proper endurance,
handling, load range, speed rating, traction, ride, tire
pressure monitoring system performance 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 an “MS” (for mud and snow).