1993 GMC Suburban Owner's Manual - Page 316

f Don't let anyone tell you that underinflation or overinfiation is all right. .!t's . not. If,your tires don't have enough air .(undarinfiaticm) you can get: * ' Too much flexing 0 Too much heat e Tire overloading * Bad wear Bad handing Bad fuel emnomy. I your-tires have bo much air (overinflation), you can: get: . f . . I . a : Unusual wear * Bad handling 0 * Rough ride Needless damage from road hazards. a monthormore. Also, check the When to Check: Checkyourtiresonce tirepressure of thesparetire. How to Check: Use a good qualitypocket-typegage to checktirepressure. will not tell youthepressure,especially if you Simplylookingatthetires haveradialtires-whichmay underinflated. look properly inflated even if they're If yourtireshavevalvecaps,besure to putthembackon.They preventleaks by keepingoutdirtandmoisture. help Special Tire inflation If youhave I6 inch tires on yourvehicle,and: - You'll bedrivingforverylongatspeedsof 66 mph (105 kmlh)to 75 rnph (120 kmlh)wherelegal,inflatetires 10 psi (70 kPa)morethan therecommended cold inflationpressure. - You'llbedriving for verylongatspeedsof 76 mph (120 kmlh) to 85 mph (135 kmlh) wherelegal, cold inflationpressureshouldbe load increasedby 10 psi (90 kPa)andyoumustalsoreduceaxle capacity by 10%. De not drive ower 85 mph (135 k d h ) ewes9 if Q it's iegal I - Inflationpressuresshouldneverexceed inflationspecifiedforthemaximum 6-50 10 psi (70 kPa)abovethe load of the tire,