How to Check and Set Tire Pressure
The right PSI for your car — and why your dashboard light is lying to you
How to Check Tire Pressure the Right Way
Proper tire pressure is one of the easiest — and most overlooked — maintenance tasks. Here's everything you need to know.
What PSI Should Your Tires Be?
Do not use the number on the tire sidewall. That's the maximum pressure the tire can handle, not the recommended operating pressure for your vehicle.
Find your vehicle's recommended tire pressure on:
- The door jamb sticker (driver's side door edge) — most reliable
- The glove box or fuel door — some vehicles list it there
- Your owner's manual
Most passenger cars run 30–35 PSI. Trucks and SUVs often run 35–45 PSI.
How to Check Tire Pressure
- Check pressure when the tires are cold — before driving or after sitting for at least 3 hours.
- Remove the valve cap from the tire stem.
- Press a tire pressure gauge firmly onto the valve stem.
- Read the pressure and compare to your door jamb spec.
- Add air if low; release air if over-inflated.
Why Your TPMS Light Isn't Enough
The Tire Pressure Monitoring System (TPMS) only warns you when pressure drops 25% below recommended. By that point, you're already getting reduced fuel economy, faster wear, and compromised handling. Check manually once a month.
Effects of Wrong Pressure
| Under-inflated | Over-inflated | |
|---|---|---|
| Wear pattern | Both edges wear faster | Center wears faster |
| Fuel economy | Worse (more rolling resistance) | Slight improvement |
| Handling | Sluggish, overheats | Harsh, less grip |
| Blowout risk | Higher (heat buildup) | Higher (impact sensitivity) |
Frequently Asked Questions
How much does tire pressure change with temperature?
For every 10°F drop in temperature, tire pressure drops about 1 PSI. So if your tires were set at 32 PSI in summer (80°F), they may read 28 PSI on a cold winter morning (40°F). Always adjust seasonally.
Can I use nitrogen in my tires?
Yes, but the benefits are modest. Nitrogen maintains pressure slightly better over time and doesn't retain moisture. It's not worth paying a premium for — just check and maintain your tire pressure monthly.
My TPMS light came on but tires look fine — what do I do?
Check all four tires with a gauge — TPMS sensors can malfunction, and a tire can be 6–7 PSI low before it visibly looks flat. Also check for a slow leak by spraying soapy water on the valve stem and tread.