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CHASSIS
184If a tire often goes flat or cannot be properly repaired due to the
size or location of a cut or other damage, it should be replaced.
If you are not sure, consult with your Lexus dealer.
If an air loss occurs while driving, do not continue driving with
a deflated tire. Driving even a short distance can damage a tire
beyond repair.
Any tires which are over 6 years old must be checked by
a qualified technician even if damage is not obvious.
Tires deteriorate with age even if they have never or seldom
been used.
This also applies to the spare tire and tires stored for future
use.
Uniform tire quality grading
This information has been prepared in accordance with
regulations issued by the National Highway Traffic Safety
Administration of the U.S. Department of Transportation.
It provides the purchasers and / or prospective
purchasers of Lexus vehicles with information on uniform
tire quality grading.
Your Lexus dealer will help answer any questions you may
have as you read this information.
DOT quality grades − All passenger vehicle tires must
conform to Federal Safety Requirements in addition to
these grades. These quality grades are molded on the
sidewall.
Treadwear − The treadwear grade is a comparative rating
based on the wear rate of the tire when tested under controlled
conditions on a specified government 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 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 A, B, C − 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 concrete. A
tire marked C may have poor traction performance.
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CHASSIS
185 Warning: The traction grade assigned to this tire is based on
braking (straight ahead) traction tests and does not include
cornering (turning) traction.
Temperature A, B, C − The temperature grades are A (the
highest), 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 failure. The grade C
corresponds to a level of performance which all passenger car
tires must meet under the Federal Motor 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 grade of this tire established for a
tire that is properly inflated and not overloaded. Excessive
speed, underinflation, or excessive loading, either separately
or in combination, can cause heat buildup and possible tire
failure.
Tire selection
When replacing a tire, use only the same size and
construction as originally installed and with the same or
greater load capacity.
Using any other size or type of tire may seriously affect
handling, ride, speedometer / odometer calibration, ground
clearance, and clearance between the body and tires or snow
chains.
Do not mix radial, belted, or conventional tires on your
vehicle.
It can cause dangerous handling characteristics, resulting in
loss of control. If you need to change from conventional tires
to radial tires or vice versa, replace them as a set.
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CHASSIS
186
INSTALLING SNOW TIRES AND
CHAINS
When to use snow tires or chains
Snow tires or chains are recommended when driving on
snow or ice.
On wet or dry roads, conventional or radial tires provide better
traction than snow or studded tires.
Snow tire selection
If you need snow tires, select the same size, construction
and load capacity as the original tires on your Lexus.
Do not use tires other than stated above. Since your vehicle
has radial tires as original equipment, make sure your snow
tires also have radial construction. Do not install studded tires
without first checking local regulations for possible restrictions.
Snow tire installation
Snow tires should be installed on all wheels.
Installing snow tires on the front wheels only can lead to an
excessive difference in road grip capability between the front
and rear tires which could cause loss of vehicle control.CAUTION:
Snow tires should be inflated to the same pressure as
the original tires.
Never drive over 120 km / h (75 mph) with any type of
snow tires.
Tire chain selection
Regulations regarding the use of tire chains vary
according to location or type of road. Always check the
local regulations before installing chains.
Use SAE Class “S” type radial tire chains, with the exception
of radial cable chains or V−bar type chains.
Chain installation
Install the chains on the front tires as tightly as possible.
Do not use tire chains on the rear tires. Retighten chains
after driving 0.5 − 1.0 km (1 / 4 − 1 / 2 mile).
When installing chains on your tires, carefully follow the
instructions of the chain manufacturer.
CAUTION:
Do not exceed 50 km / h (30 mph) or the chain
manufacturer’s recommended speed limit, whichever
is lower.
Drive carefully avoiding bumps, holes, and sharp turns,
which may cause the vehicle to bounce.
Avoid sharp turns or locked−wheel braking, as use of
chains may adversely affect vehicle handling.