TIRES
Check Tire Pressure and Tread at Home
- Level
- Beginner
- Time
- 20 minutes
- Tools
- Dial or digital tire gauge, quarter, air compressor or gas-station hose
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Underinflated tires wear the shoulders, overinflated tires wear the center, and both cost you fuel and stopping distance. The number on the tire sidewall is the maximum pressure — not what you should run daily. The cold PSI on the driver's door jamb (or manual) is the target.
When to measure — "cold" matters
Check pressure when the car has sat at least 3 hours or before the first mile of the day. Driving heats air inside the tire and raises readings 2–4 PSI — a false "good" reading.
Example sticker values (always use yours):
| Position | Typical cold PSI (many sedans) |
|---|---|
| Front | 32–35 PSI |
| Rear | 32–35 PSI (may differ on trucks) |
Some SUVs show 35 front / 38 rear when loaded — the manual explains which applies.
Step-by-step with a dial gauge
- Remove the valve cap — stash it in your pocket so it does not roll into a drain.
- Press the gauge squarely on the valve stem until the hiss stops.
- Read the gauge. Compare to door-jamb cold PSI for that axle.
- Add air in short bursts if low; recheck. Release pressure with the gauge stem if over by more than 2 PSI.
- Replace caps — they keep moisture out of the valve core.
Check the spare if you have a full-size or temporary spare with a valve stem. Many space-saver spares want 60 PSI — read the sidewall.
Tread depth — quarter test
Insert a quarter into the tread groove with Washington's head down. If you can see the top of his head, you are near 4/32" or less in that spot — plan replacement soon. For a rough numeric check, use a tread depth gauge ($5 at any parts store); replace at 2/32" legal minimum, but wet traction drops well before that.
Look for:
- Cupping or scalloped edges — often suspension or rotation issues.
- One edge worn — chronic underinflation or alignment.
- Bulge or cut in sidewall — replace immediately; do not plug sidewalls.
Rotate tires per manual (often every 5,000–7,500 miles) so wear evens out.
TPMS light basics
A solid TPMS light after a cold morning often means one tire dropped 5+ PSI — check all four before driving far. A flashing TPMS light at startup usually means a sensor or system fault — air pressure may still look fine on a gauge.
We do not interpret sensor fault codes here; a shop with a TPMS tool can read which wheel failed.
Tools worth owning
- Dial gauge (0–60 PSI) — more repeatable than many pencil gauges.
- Portable 12V inflator — useful after temperature swings (roughly 1 PSI change per 10°F).