Jeep 2009 Grand Cherokee SRT - Owner Manual - Manual (Page 317)

These indicators are molded into the bottom of the tread
grooves and will appear as bands when the tread depth
becomes 1/16 inch (2 mm). When the indicators appear
in 2 or more adjacent grooves, the tire should be replaced.
Many states have laws requiring tire replacement at this
point.
Life of Tire
The service life of a tire is dependent upon varying
factors including but not limited to:
• Driving style
• Tire pressure
• Distance driven
WARNING!
All tires should be replaced after six years, regardless
of the remaining tread. Failure to follow this warning
can result in sudden tire failure. You could lose
control and have an accident resulting in serious
injury.
1 — Worn Tire
2 — New Tire
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