tires Lexus IS F 2008 Do-It-Yourself Maintenance /

413
6-1. Specifications
6
Vehicle specifications
Radial tires or bias-ply tires
A radial tire has “RADIAL” on the sidewall. A tire not marked “RADIAL” is
a bias-ply tire.
TUBELESS or TUBE TYPE
A tubeless tire does not have a tube and air is directly filled in the tire. A
tube type tire has a tube inside the ti re and the tube maintains the air pres-
sure.
Load limit at maximum cold tire inflation pressure ( P. 302)
Maximum cold tire inflation pressure ( P. 4 0 7 )
This means the pressure to which a tire may be inflated.
Uniform tire quality grading
For details, see “Uniform tire quality grading” that follows.
Summer tire or all season tire (P. 302)
An all season tire has “M+S” on the sidewall. A tire not marked “M+S” is a
summer tire.
“TEMPORARY USE ONLY” ( P. 3 7 9 )
A compact spare tire is identified by the phrase “TEMPORARY USE
ONLY” molded into its sidewall. This tire is designed for temporary
emergency use only.

416
6-1. Specifications
■DOT quality grades
All passenger vehicle tires must co nform to Federal Safety Require-
ments in addition to these grades. Quality grades can be found where
applicable on the tire sidewall between tread shoulder and maximum
section width.
For example: Treadwear 200 Traction AA Temperature A
■ Treadwear
The treadwear grade is a comparative rating based on the wear rate of
the tire when tested under controll ed conditions on a specified gov-
ernment test course.
For example, 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 de pends upon the actual conditions of
their use, however, and may depart significantly from the norm due to varia-
tions in driving habits, service practices and differences in road characteris-
tics and climate.
■ Traction AA, A, B, C
The traction grades, from highest to lowest, are AA, A, B and C, and
they represent the tire's ability to stop on wet pavement as measured
under controlled condit ions on specified government test surfaces of
asphalt and concrete.
A tire marked C may have poor traction performance.
Warning: The traction grade assigned to this tire is based on braking
(straight ahead) traction tests and does not include cornering (turning) trac-
tion.

417
6-1. Specifications
6
Vehicle specifications
■Temperature A, B, C
The temperature grades are A (the hi ghest), B, and C, representing
the tire's resistance to the generation of heat and its ability to dissipate
heat when tested under controlled conditions on a specified indoor
laboratory test wheel.
Sustained high temperature can cause the material of the tire to degenerate
and reduce tire life, and excessive temperature can lead to sudden tire fail-
ure.
The grade C corresponds to a level of performance which all passenger car
tires must meet under the Federal Mo tor Vehicle Safety Standard No. 109.
Grades B and A represent higher levels of performance on the laboratory
test wheel than the minimum required by law.
Warning: The temperature grades for this tire are established for a tire that
is properly inflated and not overloaded.
Excessive speed, underinflation, or excess ive loading, either separately or in
combination, can cause heat build up and possible tire failure.
Glossary of tire terminology
Tire related termMeaning
Cold tire inflation pres-
sureTire pressure when the vehicle has been parked for
three hours or more, or has not been driven more
than 1 mile or 1.5 km under that condition
Maximum inflation pres-
sureThe maximum cold inflated pressure to which a tire
may be inflated, shown on the sidewall of the tire
Recommended inflation
pressureCold tire inflation pressure recommended by a man-
ufacturer.
Accessory weight
The combined weight (in excess of those standard
items which may be replaced) of transmission, power
steering, power brakes, power windows, power seats,
radio and heater, to the extent that these items are
available as factory-installed equipment (whether
installed or not)

446
Alphabetical index
Tachometer..................................................128
Tail lights Switch ........................................................139
Talk switch*
Telephone switch*
Theft deterrent system Alarm ........................................................... 72
Engine immobilizer system ............. 70
Theft prevention labels .......................... 74
Tire inflation pressure .........................307
Tire information Glossary................................................... 417
Size ............................................................. 414
Tire identification number ............... 414
Uniform tire quality grading ...........415
Tires Chains ...................................................... 180
Checking ............................................... 296
If you have a flat tire .......................... 374
Inflation pressure................................ 307
Inflation pressure sensor................ 296
Information.............................................. 412
Replacing ............................................... 374
Rotating tires ......................................... 301
Size ........................................................... 407
Snow tires ............................................... 180
Tools ........................................................... 374
Total load capacity ................................ 179
Towing Dinghy towing ...................................... 183
Emergency towing ...........................340
Trailer towing.........................................182 TRAC ..........................................................166
Traction control.......................................166
Transmission shift switches.......120, 122
Trip meter ................................................. 128
Trunk
Extending a space ............................. 247
Opener ........................................................41
Trunk light Trunk light ................................................. 42
Wattage ................................................. 408
Turn signal lights Replacing light bulbs ....................... 334
Switch ........................................................ 126
Wattage ................................................. 408
Vanity lights Vanity lights...........................................234
Wattage ................................................. 408
Vanity mirrors ........................................ 234
VDIM...........................................................166
Vehicle dynamics integrated management .........................................166
Vehicle identification number......... 399
Vehicle stability control .......................166
Ventilators ............................................... 244
VSC .............................................................166T
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