1993 Chevrolet Astro Owner's Manual - Page 284

Sewice & Appearance Cam When lt3 Time for New Tires K1656 Oneway to tell whenit'stimefornewtires is to check the treadwear 2/32 inch (1.6 mm)or indicators,whichwillappearwhenyourtireshaveonly less of treadremaining. You needanewtire Youcansee if: the indicatorsatthreeplacesaroundthetire. to show You canseecordorfabricshowingthroughthetire'srubber. Thetread or sidewall is cracked,cutorsnaggeddeepenough cord or fabric. The tire has a bump, bulge or split. The tire hasapuncture,cut, orotherdamage thatcan'tberepaired because of the size or location of the damage. Buying New Tires To find out what kind and size of tiresyouneed,lookatthe CertificationRire it wasnewhadaTire label.Thetiresinstalledonyourvehiclewhen PerformanceCriteriaSpecification(TPCSpec)numberoneachtire'ssidewall. Whenyougetnewtires,getoneswiththatsameTPCSpecnumber.That way, your vehicle will continue to have tires that are designed to give proper endurance,handling,speedrating,traction,rideandotherthingsduring normal service on your vehicle. Ifyour tireshaveanall-seasontreaddesign, "MS" (formudandsnow). the TPC numberwillbefollowedbya 6-48