Tire Pressure Monitoring System - Audi A8 2018 Owner's Manual

Wheels
"XL" "xl" "EXTRA LOAD" or "RF"
I I I
on the sidewall.
Rim
means a metal support for a tire
or a tire and tube assembly upon
which the tire beads are seated.
Rim diameter
means nominal diameter of the
bead seat . If you change your
wheel size, you will have to pur -
chase new tires to match the new
rim diameter .
Rim size designation
means rim diameter and width .
Rim width
means nominal distance between
rim flanges.
Sidewall
means that portion of a tire be-
tween the tread and bead .
Speed rating (letter code)
means the speed at which a tire is
designed to be driven for extend-
ed periods of time. The ratings
range from 93 mph (150 km/h)
to 186 mph (298 km/h)¢ table
on page 284 . You may not find
this information on all tires be-
cause it is not required by law .
288
The speed rating letter code,
where applicable, is molded on
the tire sidewall and indicates the
maximum permissible vehicle
speeds ¢
.1,.
in Winter tires on
page 298 .
Tire pressure monitoring
system*
means a system that detects
when one or mo re of a vehicle 's
tires are underinflated and illumi-
nates a low tire pressure warning
telltale .
Tread
means that portion of a tire that
comes into contact with the road .
Tread separation
means pulling away of the tread
from the tire carcass .
Treadwear indicators (TWI )
means the projections within t he
principal grooves designed to give
a visual indication of the degrees
of wear of the tread. See
¢
page 292, Treadwear indicator
for more information on measur-
ing tire wear. .,.