Chevrolet 1995 Astro Cargo Owner's Manual page 252

When It's Time for New Tires
Tread Wear
Indicators
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
remaining.
You need a new tire if:
You can
see
the indicators at three or more places around the tire.
You
can see cord or fabric showing through the tire's rubber.
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 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 an "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.
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