DEPARTMENT OF TRANSPORTATION UNIFORM
TIRE QUALITY GRADES
The following describes the tire grading categories estab-
lished by the National highway Traffic Safety Adminis-
tration. The specific grade rating assigned by the tire’s
manufacturer in each category is shown on the sidewall
of the tires on your car.
All Passenger Car Tires Must Conform to Federal 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 con-
ditions on a specified government test course. For ex-
ample, a tire graded 150 would wear one and a half (1
1/2) 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.
Traction Grades
The traction grades, from highest to lowest, are A, B, and
C, and they represent the tire’s ability to stop on wet
pavement as measured under controlled conditions on
specified government test surfaces of asphalt and con-
crete. A tire marked C may have poor traction perfor-
mance.
WARNING!
The traction grade is based on braking (straight-
ahead) traction tests and does not include cornering
(turning) performance.
IF YOU NEED CONSUMER ASSISTANCE 301
9
Storing Your Vehicle..................... 268
Sun Roof............................. 120
Sunglass Storage....................... 114
Supplemental Restraint System - Airbag....... 35
System, Navigation..................... 166
Tachometer........................... 134
Telescoping Steering Column.............. 106
Temperature Control, Automatic............ 171
Temperature Gauge, Engine Coolant......137,225
Theft Alarm............................ 22
Theft System........................... 22
Tie Down Hooks, Cargo.................. 126
Tilt Steering Column.................... 106
Tire and Loading Information Placard....... 201
Tire Identification Number (TIN)........... 200
Tire Markings......................... 197
Tire Safety Information................... 197
TIREFIT.............................. 226
Tires ...........................57,205,301
Air Pressure......................... 205
Alignment.......................... 210
Chains............................. 211General Information................... 205
High Speed......................... 207
Inflation Pressures.................... 206
Load Capacity....................201,202
Quality Grading...................... 301
Radial............................. 208
Replacement......................... 209
Rotation............................ 212
Safety...........................197,205
Sizes............................... 198
Snow Tires.......................... 212
Spinning............................ 208
Tread Wear Indicators.................. 209
Towing
Behind a Motor Home................. 222
Disabled Vehicle...................... 233
Recreational......................... 222
Towing Vehicle Behind a Motor Home....... 222
Traction Control........................ 107
Traction Control Switch.................. 107
Transmission.......................... 259
Automatic........................183,259
Fluid.............................. 276
314 INDEX
