The spare can get old without getting worn

A spare tire spends most of its life out of sight, so it can avoid tread wear while still experiencing years of heat cycles and natural rubber aging. A compact spare in a trunk well may look nearly new because the molding marks are still visible, yet its calendar age can be very different from the road tires you replaced last year.

That is why spare-tire maintenance is a separate task. You need to know the tire's age, pressure, physical condition, wheel condition, and the vehicle's rules for using that spare. A full-size matching spare and a temporary-use compact spare can have different pressure, speed, distance, rotation, and replacement guidance.

Three spare-tire checks answer different questions

DOT date code
Estimating when the tire was manufactured and comparing that age with manufacturer guidance

The four-digit week-and-year date code is part of the Tire Identification Number. It may be molded on only one sidewall, so it is not always visible without accessing the inner side.

Pressure check
Finding a spare that has slowly lost air while sitting unused

Temporary spares can use a substantially different pressure from the road tires. Use the vehicle label or owner's manual rather than copying the PSI from another tire.

Physical inspection
Finding cracks, bulges, cuts, bead damage, corrosion, or previous repair that can make the spare a poor roadside backup

Tread that looks deep does not cancel structural damage or age-related deterioration elsewhere on the tire.

Inspect the spare before a long trip

  • Confirm the spare is actually present and that the jack, lug-wrench or tool kit, wheel-lock key, and any required extension are still in the vehicle.
  • Read the spare's pressure requirement from the vehicle placard or owner's manual and measure it cold with a reliable gauge.
  • Find the DOT Tire Identification Number and record the manufacture date rather than guessing age from appearance.
  • Check accessible sidewalls and tread for cracking, cuts, bulges, exposed cord, deformation, or contamination.
  • Inspect the wheel for severe corrosion, bending, or damage around the lug holes and valve stem.
  • Confirm whether the spare is temporary-use, full-size matching, or full-size nonmatching and review the vehicle's speed, distance, axle, and drivetrain restrictions.

Safety check

Do not turn one age number into a rule for every spare

Vehicle makers and tire manufacturers publish their own inspection and replacement guidance, and the correct decision can depend on tire construction, use, storage, and condition. Follow the guidance for the tire and vehicle you actually have. If the date code is unreadable, the spare is old enough that its history is uncertain, or cracking or deformation is present, have a tire professional evaluate it before depending on it for highway use.

Keep the spare useful instead of merely present

  1. 01
    Add the spare to routine pressure checks

    A hidden tire can lose air slowly for months. Checking it before road-trip season or regular maintenance visits is more useful than discovering low pressure on the shoulder of an Interstate.

  2. 02
    Track its age with the other tires

    When you replace road tires, note the spare's manufacture date too. It may be much older than the set on the ground.

  3. 03
    Replace based on condition and documented guidance

    Do not wait for the spare to wear out. Use the owner's manual, tire-maker information, and professional inspection to decide when age or damage has ended its useful life.

  4. 04
    Review how the spare changes vehicle operation

    If it is a compact or different-size spare, learn the approved installation position, speed and distance restrictions, and any AWD or differential limitations before an emergency forces the decision.