When you inflate the tires to the recommended inflation pressures, the factory-installed wheels and tires are designed to handle loads to the wheel's rated load capacity. Incorrect tire pressures, or under-inflated tires, can cause the following conditions:
| • | Vehicle handling problems |
| • | Poor fuel economy |
| • | Shortened tire life |
| • | Tire overloading |
Inspect the tire pressure when the following apply:
| • | The tires are cool. |
| • | The vehicle has not been driven for more than 3 hours. |
| • | The vehicle has been driven less than 1.6 km (1 mi). |
Inspect the tires monthly or before any extended trip. Adjust the tire pressure to the specifications on the tire placard. Install the valve caps or extensions on the valves. These keep out dust and water.
The kilopascal (kPa) is the metric term for tire inflation pressure. The tire pressure may be printed in both kilopascal (kPa) and psi. One psi equals 6.9 kPa.
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 | |||
Tires with a higher than recommended pressure can cause the following conditions:
| • | A hard ride |
| • | Tire bruising |
| • | Rapid tread wear at the center of the tire |
Tires with a lower than recommended pressure can cause the following conditions:
| • | A tire squeal on turns |
| • | Hard steering |
| • | Rapid wear and uneven wear on the edge of the tread |
| • | Tire rim bruises and tire rim rupture |
| • | Tire cord breakage |
| • | High tire temperatures |
| • | Reduced vehicle handling |
| • | High fuel consumption |
Unequal pressure on the same axle can cause the following conditions:
| • | Uneven braking |
| • | Steering lead |
| • | Reduced vehicle handling |
