Cadillac DTS 2011 Owner's Manual page 361

(E) Tire Inflation The temporary use tire or
:
compact spare tire should be inflated to 60 psi
(420 kPa). For more information on tire pressure
and inflation see Inflation - Tire Pressure on
page 6 57 and Spare Tire on page 6 93.
(F) Tire Size A combination of letters and
:
numbers define a tire's width, height, aspect ratio,
construction type and service description. The
letter T as the first character in the tire size means
the tire is for temporary use only.
(G) TPC Spec (Tire Performance Criteria
Specification) Original equipment tires designed
:
to GM's specific tire performance criteria have a
TPC specification code molded onto the sidewall.
GM's TPC specifications meet or exceed all
federal safety guidelines.
Light Truck Tire Example
(A) Tire Size The tire size code is a combination
:
of letters and numbers used to define a particular
tire's width, height, aspect ratio, construction type
and service description. See the Tire Size
illustration later in this section for more detail.
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