BMW Z4, Owner'S Manual

Page: 256 / 330

Tire identification marks
Tire size
245/45 R 18 96 Y
245: nominal width in mm
45: aspect ratio in %
R: radial tire code
18: rim diameter in inches
96: load rating, not for ZR tires
Y: speed rating, before the R on ZR tires
Maximum tire load
Maximum tire load is the maximum permissible
weight for which the tire is approved.
Locate the maximum tire load on the tire sidewall
and the Gross Axle Weight Rating – GAWR – on
the certification label on the driver door B-pillar.
Divide the tire load by 1.1. It must be greater
than one-half of the vehicle’s Gross Axle Weight
Rating – GAWR. Note, front vs. rear GAWR and
tire loads, respectively.
Speed letter
Q = up to 100 mph/160 km/h
R = up to 106 mph/170 km/h
S = up to 112 mph/180 km/h
T = up to 118 mph/190 km/h
H = up to 131 mph/210 km/h
V = up to 150 mph/240 km/h
W = up to 167 mph/270 km/h
Y = up to 186 mph/300 km/h
Tire Identification Number
DOT code: DOT xxxx xxx 0119
xxxx: manufacturer code for the tire brand
xxx: tire size and tire design
0119: tire age
Tires with DOT codes meet the guidelines of the
U.S. Department of Transportation.
Tire age
Recommendation
Regardless of the tire tread, replace tires at least
every 6 years.
Manufacture date
You can find the manufacture date of the tire on
the tire's sidewall.
Designation Manufacture date
DOT … 0119 1st week, 2019
Uniform Tire Quality Grading
Quality grades can be found where applicable on
the tire sidewall between tread shoulder and
maximum section width.
E.g.: Treadwear 200; Traction AA; Temperature
A
DOT Quality Grades
Treadwear
Traction AA A B C
Temperature A B C
All passenger vehicle tires must conform to Fed‐
eral Safety Requirements in addition to these
grades.
Treadwear
The treadwear grade is a comparative rating
based on the wear rate of the tire when tested
under controlled conditions on a specified gov‐
ernment test course. E.g., a tire graded 150
would wear one and one-half, 1 g, times as well
on the government course as a tire graded 100.
The relative performance of tires depends upon
the actual conditions of their use, however, and
may depart significantly from the norm due to
variations in driving habits, service practices and
differences in road characteristics and climate.
Seite 256
MOBILITY
Wheels and tires
256
Online Edition for Part no. 01402779113 - II/19