Tire Pressure & Tread

Tires are the only part of your car touching the road. Underinflated or worn tires take longer to stop, hydroplane more easily and can fail at highway speed. A few minutes a month keeps them safe.

• All drivers
• Work vehicles

Tire pressure

• Find the correct pressure on the placard inside the driver’s door jamb or in the owner’s manual.
• The number on the tire sidewall is the maximum pressure, not the recommended pressure.
• Check pressure at least once a month and before long trips, with a gauge, when tires are cold (before driving or after sitting a few hours).
• Pressure drops about 1 psi for every 10°F drop in temperature, so check more often as weather cools.
• Don’t forget the spare.

The TPMS warning light

Newer cars have a tire pressure monitoring system. A steady light means at least one tire is significantly underinflated; check and fill it. A flashing light that then stays on usually means a system problem. TPMS warns you late, so it doesn’t replace monthly checks.

Tread depth

• Most states require at least 2/32 inch of tread, but wet-road performance drops well before that. Many experts recommend replacing tires at 4/32 inch.
• Penny test: put a penny in the tread with Lincoln’s head down. If you can see the top of his head, the tread is at or below 2/32 inch.
• Wear bars: raised bars across the tread grooves. When the tread is level with them, replace the tire.
• Uneven wear can mean alignment, inflation or suspension problems.

Inspect for damage

• Bulges or bubbles in the sidewall (replace immediately)
• Cuts, cracks or punctures
• Nails or screws in the tread
• Cracking from age or sun

Tire age

Rubber breaks down over time even if the tread looks fine. The four-digit DOT date code on the sidewall shows the week and year it was made (for example, 2321 means the 23rd week of 2021). Many manufacturers recommend replacing tires after 6 to 10 years regardless of tread.

Other care

• Rotate tires as recommended (often every 5,000 to 8,000 miles).
• Don’t overload the vehicle. See Work Pickups.
• Register your tires and check for recalls on NHTSA’s site.

Last updated: October 2, 2026