Chevrolet Spark EV 2014 Owner's Manual page 282

The rubber in tires ages over time.
This also applies to the spare tire,
if the vehicle has one, even if it is
never used. Multiple factors
including temperatures, loading
conditions, and inflation pressure
maintenance affect how fast aging
takes place. GM recommends
that tires, including the spare if
equipped, be replaced after six
years, regardless of tread wear.
The tire manufacturer date is the
last four digits of the DOT Tire
Identification Number (TIN) which is
molded into one side of the tire
sidewall. The first two digits
represent the week (01 52) and
the last two digits, the year. For
example, the third week of the year
2010 would have a four-digit DOT
date of 0310.
Tires age when stored normally
mounted on a parked vehicle. Park
a vehicle that will be stored for at
least a month in a cool, dry, clean
area away from direct sunlight to
slow aging. This area should be
free of grease, gasoline, or other
substances that can deteriorate
rubber.
Parking for an extended period can
cause flat spots on the tires that
may result in vibrations while
driving. When storing a vehicle for
at least a month, remove the tires or
raise the vehicle to reduce the
weight from the tires.
GM has developed and matched
specific tires for the vehicle.
The original equipment tires
installed were designed to
meet General Motors Tire
Performance Criteria
Specification (TPC Spec)
system rating. When
replacement tires are needed,
GM strongly recommends
buying tires with the same TPC
Spec rating.
GM's exclusive TPC Spec
system considers over a
dozen critical specifications that
impact the overall performance
of the vehicle, including brake
system performance, ride and
handling, traction control, and
tire pressure monitoring
performance. GM's TPC Spec
number is molded onto the tire's
sidewall near the tire size. If the
tires have an all-season tread
design, the TPC spec number
will be followed by MS, for mud
and snow. See
GM recommends replacing
worn tires in complete sets of
four. Uniform tread depth on all
tires will help to maintain the
performance of the vehicle.
Braking and handling
performance may be adversely
affected if all the tires are not
replaced at the same time.
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