1993 Chevrolet Suburban Owner's Manual - Page 318

When It's Time for New Tires TREAD WEAR INDICATORS K1656 Oneway to tell when it's timefornewtires is to checkthetreadwear 2/32 inch (1,6 mm)or indicators,whichwillappearwhenyourtireshaveonly lessoftreadremaining. You needa new tireif: You canseetheindicatorsatthreeplacesaroundthe You canseecordorfabricshowingthroughthetire'srubber. The tread or sidewalliscracked,cut cord or fabric. The tire hasabump,bulge orsnaggeddeepenough tire. to show or split. The tire hasapuncture,cut, orotherdamagethatcan'tberepairedwell because of the size or location of the damage, Buying New Tires To find out what kind and size of tiresyouneed, look at the Certificationnire label.ThetiresinstalledonyourvehiclewhenitwasnewhadaTire PerformanceCriteriaSpecification(TPCSpec)numberoneachtire'ssidewall. Whenyougetnewtires,getoneswiththatsameTPCSpecnumber.That way,yourvehicle will continue to have tires that are designed to give proper endurance,handling,speedrating,traction,rideandotherthingsduring normal service on yourvehicle. If your tires haveanall-seasontreaddesign, theTPCnumber will be followed by a "MS" (formudandsnow). 6-53