Damage

Periodically inspect the tire treads and sidewalls for damage (such as bulges in the tread or sidewalls, cracks in the tread groove and separation in the tread or sidewall). If damage is observed or suspected have the tire inspected by a tire professional. Tires can be damaged during off-road use, so inspection after off-road use is also recommended.
WARNING: Age
Tires degrade over time depending on many factors such as
weather, storage conditions, and conditions of use (load, speed,
inflation pressure, etc.) the tires experience throughout their lives.
In general, tires should be replaced after six years regardless of tread wear. However, heat caused by hot climates or frequent high loading conditions can accelerate the aging process and may require tires to be replaced more frequently.
You should replace your spare tire when you replace the road tires or after six years due to aging even if it has not been used.
See also:
If the airbag readiness lamp is lit, do the following
The driver and/or adult passengers should check for any objects that
may be lodged underneath the front passenger seat or cargo interfering
with the seat.
If objects are lodged and/or cargo is ...
Special operating conditions
If you operate your vehicle primarily in any of the following
conditions,
you need to perform additional maintenance as indicated. If you
occasionally operate your vehicle under any of these con ...
Roof rack system (if equipped)
Loads should never be placed directly on the roof panel. For proper
function of the roof rack system, loads must be placed directly on
crossbars affixed to the roof rack side rails. Your vehicle m ...
