Dodge 2008 Sprinter Owner's Manual page 198

Controls in detail
Driving and parking
causes and consequences of tire
wear
measures to be taken in the event of
tire damage
tire types for certain regions, areas
of operation or conditions of vehicle
use
interchangeability of tires, etc.
3
Modifications to the brake system or
wheels are not permissible, nor is the
use of spacer plates or brake dust
shields. Any such modifications will in-
validate the vehicle's general operating
permit.
196
Warning
If you feel a sudden significant vibration
or ride disturbance, or you suspect that
possible damage to your vehicle has oc-
curred, you should turn on the hazard
warning flashers, carefully slow down,
and drive with caution to an area which is
a safe distance from the road.
Inspect the tires and the vehicle undercar-
riage for possible damage. If the vehicle
or tires appear unsafe, have the vehicle
towed to the nearest authorized Sprinter
Dealer or tire dealer for repairs.
Treadwear indicators (TWI) are required
G
by law. These indicators are located in
six places on the tread circumference
and become visible at a tread depth of
approximately 1/16 in (1.6 mm), at
which point the tire is considered worn
and should be replaced.
The Treadwear Indicator appears as a
solid band across the tread.