Fill Tires to the Door-Jamb Number, Not the Sidewall Number

The Problem

A low-tire warning comes on, you drag the hose over at the gas station, look at the tire for a number, and find one: "44 PSI" molded into the sidewall. So you fill to 44 — and now the tire is overinflated, riding harsh, wearing its center, and gripping worse. The sidewall number is the tire's maximum rated pressure, not what your vehicle wants in it.

The Technique

1. Open the driver's door and find the placard on the door jamb. That sticker lists the manufacturer's recommended pressure for your vehicle's front and rear tires — usually somewhere in the low-to-mid 30s.
2. Unscrew the valve cap and check the current pressure with a gauge. (Yes, there's a cap. Check anyway — the dashboard warning tells you a tire is low, not how low.)
3. Fill to the placard number, checking with the gauge as you go — many station air pumps beep when they reach a preset pressure.
4. Top off the other three while you're there; they're rarely far behind.