Chevrolet 1993 S-10 Pickup Owner's Manual page 294

Service & Appearance Care
When It's Time for New Tires
K1656
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 2/32 inch (1.6 mm) or
less of tread remaining.
You need a new tire if:
You can see the indicators at three 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
because of the size or location of the damage.
Buying New Eres
To find out what kind and size of tires you need, look at the CertificationRire
label. The tires installed on your vehicle when it was mew 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 a "MS" (for mud and snow).
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