Lexus ES-300 2001 Manual page 452

If you have tire damage such as cuts, splits, cracks
deep enough to expose the fabric, or bulges
indicating internal damage, the tire should be
replaced.
If 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 car tires must
conform to Federal Safety Requirements 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 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 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
CHASSIS
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