Tread wear indicator
The tires have wear indicator strips running across or parallel to the tread. The letters TWI are printed on
the side of the tire. When approximately 1/16" (1.6 mm) is left on the tread, these strips become visible
and indicate that the tire should be replaced. Tires with less than 1/16" (1.6 mm) tread offer very poor
traction.
When replacing worn tires, it is recommended that the tire be identical in type (radial) and size as the
one being replaced. Using a tire of the same make (manufacturer) will prevent alteration of the driving
characteristics of the vehicle.
pg. 129 General information
New tires
Remember that tires are perishable goods. As of 2000, the manufacturing week and year (Department of
Transportation (DOT) stamp) will be indicated with 4 digits (e.g. 1502 means that the tire illustrated was
manufactured during week 15 of 2002).
Tire age
Tires degrade over time, even when they are not being used, which can affect their reliability and
roadholding characteristics. Therefore, all tires older than 6 years (including the spare tire and winter
tires) should be inspected by a qualified technician, regardless of appearance or mileage. Heat caused by
hot climates or frequent high loading conditions can accelerate the aging process.
A tire's age can be determined by the DOT stamp on the sidewall (see the illustration above).
