Cadillac 2009 Automobile User Manual


 
Buying New Tires
GM has developed and matched specific tires for
your vehicle. The original equipment tires installed
on your vehicle, when it was new, were designed
to meet General Motors Tire Performance Criteria
Specification (TPC Spec) system rating. If you need
replacement tires, GM strongly recommends that
you get tires with the same TPC Spec rating. This
way, your vehicle will continue to have tires that are
designed to give the same performance and vehicle
safety, during normal use, as the original tires.
GM’s exclusive TPC Spec system considers
over a dozen critical specifications that impact the
overall performance of your vehicle, including brake
system performance, ride and handling, traction
control, and tire pressure monitoring performance.
GM’s TPC Spec number is molded onto the tire’s
sidewall near the tire size. If the tires have an
all-season tread design, the TPC Spec number
will be followed by an MS for mud and snow.
See Tire Sidewall Labeling on page 5-56 for
additional information.
GM recommends replacing tires in sets of four.
This is because uniform tread depth on all tires
will help keep your vehicle performing most like
it did when the tires were new. Replacing less
than a full set of tires can affect the braking and
handling performance of your vehicle.
The optional 18-inch performance tires,
size 255/45ZR18 99Y, used on some vehicles,
meets the General Motors Tire Performance
Criteria Specification (TPC Spec) rating but the
TPC Spec code has not been molded onto the tire’s
sidewall. If your vehicle has these tires, and you
need to replace them, you can still get these TPC
Spec rated tires by asking your GM dealer. Your
GM dealer can order these tires by part number.
This way, your vehicle will continue to give the
proper endurance, handling, traction, and ride
as the original tires.
Winter tires with the same speed rating as your
original equipment tires may not be available for H,
V, W, Y and ZR speed rated tires. If you choose
snow tires with a lower speed rating, never exceed
the tire’s maximum speed capability.
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