GM Service Manual Online
For 1990-2009 cars only

This vehicle has been engineered to operate up to the stated load capacity with wheel and tire assemblies of the type, size, construction, and configuration as originally installed. Maintenance of the tire inflation pressures is critical to the continued satisfactory performance, handling, and operating economy of the vehicle. Operation with incorrectly or improperly inflated tires can adversely affect vehicle performance and may contribute to the following:

    • Reduced fuel economy
    • Tire overloading
    • Shortened tire life
    • Excessive tire wear
    • Uneven tire wear
    • Vehicle handling concerns

Inspect the tire pressures when the vehicle has not been driven for at least 3 hours or not more than 1.6 km (1 mi) and when the tires are cool to the touch.

Tire inflation pressures should be inspected monthly and before an extended trip and adjusted to meet the specifications listed for the particular vehicle. Replace any missing or damaged tire valve stem extensions and/or caps to prevent the intrusion of water and contaminates.

One pound per square inch (psi) equals 6.9 kilopascals (kPa). The following table illustrates the conversion of kilopascals to pounds per square inch:

Inflation Pressure Conversion (Kilopascals to PSI)

kPa

psi

kPa

psi

140

20

215

31

145

21

220

32

155

22

230

33

160

23

235

34

165

24

240

35

170

25

250

36

180

26

275

40

185

27

310

45

190

28

345

50

200

29

380

55

205

30

415

60

Conversion: 6.9 kPa = 1 psi

For the correct inflation pressures refer to the vehicle's tire placard.

Tires inflated to a higher than recommended pressure can contribute to the following conditions:

    • A hard ride
    • Tire bruising
    • Rapid tread wear at the center of the tire

Tires inflated to a lower than recommended pressure can contribute to the following conditions:

    • Tire squeal on turns
    • Hard steering
    • Rapid and/or uneven wear on the outer edges of the tread
    • Tire rim bruises and tire rim rupture
    • Tire cord breakage
    • High tire temperatures
    • Sluggish vehicle handling
    • Higher fuel consumption

Unequal pressure on the same axle can cause the following conditions:

    • Uneven braking action
    • Steering lead
    • Imprecise vehicle handling