Lexus RX300 Manual page 276

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.
Do not use tires or wheels other than the manufacturer's
recommended size.
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.
CHASSIS
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