Why Tire Pressure Matters
Proper tire pressure is critical for safety, fuel efficiency, and tire longevity. Underinflated tires increase rolling resistance (reducing MPG by up to 3%), cause uneven wear, and generate excess heat that can lead to blowouts. Overinflated tires reduce traction and cause center-tread wear.
Tire pressure changes by approximately 1 PSI for every 10 degrees Fahrenheit change in temperature. This is why your tire pressure warning light often comes on during cold mornings.
Pressure Conversion & Temperature Adjustment
Recommended Tire Pressure by Vehicle
| Vehicle Type | Front PSI | Rear PSI | Max PSI |
|---|---|---|---|
| Compact Car | 30-35 | 30-35 | 44 |
| Sedan | 32-36 | 32-36 | 44 |
| SUV | 33-38 | 33-38 | 44 |
| Truck (unloaded) | 35-40 | 35-40 | 80 |
| Truck (loaded) | 40-45 | 55-80 | 80 |
Frequently Asked Questions
When should I check tire pressure?
Check when tires are cold (haven't been driven for 3+ hours). Driving heats the air inside, increasing pressure by 3-5 PSI and giving an inaccurate reading. Check at least once a month and before long trips.
Should I use the pressure on the tire sidewall?
No! The number on the tire sidewall is the maximum pressure, not the recommended pressure. Use the sticker on the driver's door jamb or your owner's manual for the correct pressure.
Does nitrogen make a difference?
Nitrogen-filled tires lose pressure more slowly (nitrogen molecules are larger) and are less affected by temperature. However, the real-world benefit is small. Regular air (78% nitrogen already) works fine with monthly pressure checks.