GMC 2003 Sierra - Manual (Page 453)

Buying New Tires
To ilrwd out whal kind and size of Uies you need, look ai
Ihe Certificationrrire la bet.
The tires Installed on your vehicle when It was new had
a Tire PeHormance Criteria Spedfcation (TPC Spec)
number gn each line's sidewall. When you get raw tines,
get ones wilh that same TPC Spec number. That way
your vehicle will continue lo have tires that are designed
to give proper enctuiarvcef handling, speed raling,
traction, ride and other things during nonmal service on
your vehicte. (f your Bras have an all-season (read
design, the TPC number wiil be followed by an “MS'" {far
mud and snnw).
If you ever replace your Bras whh ihoae not having a
TPC Spec number, make sura they ane the same size^
load range, speed rating and construction type (bias,
bias-belted or radial) as your original tines.
A CAUTION:
Mixing tires could cause you to lose control
while driving. |f you mix tires of different sizes
or types {radial and bias-belted tires), you
could have a crash. Using tires of different
sizes may also cause damage to your vehicle.
Be sure to use the same size and type tires pn
all wheels.
A CAUTION:
If you use bias-ply tires on your vehicle, the
wheel rim ffanges could develop cracks after
many miles of driving. A tire and/or wheel
could fail suddenly, causing a crash. Use only
radial'ply tires with the wheels on your vehicle.
5-7S