Lexus GS430 User Manual page 588

CHASSIS
The tires on your Lexus have built−in tread wear
indicators to help you know when the tires need
replacement. When the tread depth wears to 1.6 mm
(0.06 in.) or less, the indicators will appear. If you can
see the indicators in two or more adjacent grooves, the
tire should be replaced.
564
Vehicles equipped with 245/40R18 93Y or
P245/40R18 93V tires: Your Lexus has been fitted with
specially developed tires which provide exceptional
dynamic performance under general road conditions.
However your riding comfort may worsen a little and
road noise may increase during driving. You may also
notice that your tires will wear more rapidly and tire grip
performance will be reduced on the snowy and/or icy
roads when compared to standard tires. Be sure to have
snow tires or tire chains on the snowy and/or icy roads
and drive carefully with the speed appropriate for road
conditions.
NOTICE
Low profile tire like 245/40R18 93Y or P245/40R18
93V may have greater damage than usual tires to
its tire wheel when receiving impact from the road
surface. Therefore, pay attention to the following.
D Be sure to use with proper tire inflation
pressure. If the tire inflation pressure is low, the
tire may have greater damage. For detailed
information about tire inflation pressure, see
page 542.
D Avoid driving onto high, sharp−edged objects
and other road hazards. Failure to do so can
lead to severe tire damage.