Symptoms
- Not sure when tires were last checked
- Tire pressure warning light comes on occasionally
- Uneven wear starting to show
Likely causes
- CommonNatural slow air loss through the tire and valveAll tires lose roughly 1–2 PSI per month even with no puncture.
- CommonTemperature swingsTire pressure drops about 1 PSI for every 10°F the temperature falls.
- PossibleSmall unnoticed leak (nail, valve stem)A slow leak needs a specific PSI drop pattern to be caught by monthly checks.
What to do
- Check tire pressure when tires are cold, ideally before driving or after the car has sat for a few hours.
- Find the recommended PSI on the sticker inside the driver's door jamb, not the number printed on the tire sidewall (that's the max, not the recommended).
- Use a reliable tire pressure gauge on each tire, including the spare if accessible.
- Add or release air to match the recommended PSI, checking again after adjusting.
- Make this a monthly habit, and always check before long road trips or seasonal temperature swings.
- If one tire consistently loses pressure faster than the others, have it checked for a slow leak.
Tools and parts
- Tire pressure gauge
- Air compressor or access to a gas station air pump
When to call a pro
If a tire loses pressure repeatedly or the TPMS light stays on after correcting pressure, have the tire inspected for a leak or the sensor checked.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.