Understanding tire pressure and the TPMS light
January 19, 2026 · 4 min read
The tire pressure monitoring system, or TPMS, exists because under-inflated tires are both a safety risk and a fuel-economy drain. When that light glows, at least one tire is meaningfully below where it should be.
The correct pressure for your vehicle is printed on a sticker in the driver's door jamb, not on the tire sidewall. The sidewall number is a maximum, while the door-jamb number is the recommendation tuned to your car.
Check pressure when tires are cold, meaning before you have driven far, since driving warms the air and raises the reading. Re-inflate any low tire to the door-jamb specification and the warning should clear.
If the light keeps returning, you may have a slow leak or a sensor that needs service. Either way, it is worth investigating rather than ignoring.
