LEXUS RX330 2006 Owners Manual

CHASSIS
580
Tire related termMeaning
Normal occupant
weight68 kg (150 lb.) times the number of occupants specified in the second \
column of
Table 1 that follows
Occupant distributiondistribution of occupants in a vehicle as specified in the third column \
of Table 1
that follows
Production options
weightthe combined weight of those installed regular production options weighi\
ng over
2.3 kg (5 lb.) in excess of those standard items which they replace, n\
ot
previously considered in curb weight or accessory weight, including heav\
y duty
brakes, ride levelers, roof rack, heavy duty battery, and special trim
Recommended
inflation pressurecold tire inflation pressure recommended by a manufacturer
Rima metal support for a tire or a tire and tube assembly upon which the ti\
re beads
are seated
Rim diameter (Wheel
diameter)nominal diameter of the bead seat
Rim size designationrim diameter and width
Rim type designationthe industry of manufacturer’s designation for a rim by style or code
Rim widthnominal distance between rim flanges

CHASSIS
581
Tire related termMeaning
Vehicle capacity
weight
(Total load capacity)the rated cargo and luggage load plus 68 kg (150 lb.) times the vehicl\
e’s
designated seating capacity
Vehicle maximum
load on the tirethe load on an individual tire that is determined by distributing to eac\
h axle its
share of the maximum loaded vehicle weight and dividing by two
Vehicle normal load
on the tirethe load on an individual tire that is determined by distributing to eac\
h axle its
share of the curb weight, accessory weight, and normal occupant weight
(distributed in accordance with Table 1 that follows) and dividing by two
Weather sidethe surface area of the rim not covered by the inflated tire

CHASSIS
582
Table 1 — Occupant loading and distribution for vehicle normal load fo\
r various designated seating
capacitiesDesignated seating capacity,number of occupants
Vehicle normal load, number of occupantsOccupant distribution in anormally loaded vehicle
2 through 422 in front
5 through 1032 in front, 1 in second seat

CHASSIS
583
TYPES OF TIRES
Determine what kind of tires your vehicle is originally
equipped with.
1. Summer tires
Summer tires are high−speed capability tires best
suited to highway driving under dry conditions.
Since summer tires do not have the same traction
performance as snow tires, summer tires are
inadequate for driving on snow−covered or icy roads.
For driving on snow −covered or icy roads, we
recommend using snow tires. If installing snow tires,
be sure to replace all four tires.
2. All season tires
All season tires are designed to provide better traction
in snow and to be adequate for driving in most winter
conditions, as well as for use all year round. All season tires, however, do not have adequate
traction performance compared with snow tires in
heavy or loose snow. Also, all season tires fall short
in acceleration and handling performance compared
with summer tires in highway driving.
The details about how to distinguish summer tires
from all season tires are described on page 573.
CAUTION

Do not mix summer and all season tires on
your vehicle as this can cause dangerous
handling characteristics, resulting in loss of
control.
 Do not use tires other than the manufacturer’s
designated tires, and never mix tires or
wheels of the sizes different from the
originals.

CHASSIS
584
ROTATING TIRES
To equalize the wear and help extend tire life,
Lexus recommends that you rotate your tires
according to the maintenance schedule. (For
scheduled maintenance information, please refer
to the “Owner’s Manual Supplement / Scheduled
Maintenance”.) However, the most appropriate
timing for tire rotation may vary according to your
driving habits and road surface conditions.
The wheel assemblies must be rotated as illustrated
above.When rotating tires, check for uneven wear and
damage. Abnormal wear is usually caused by
incorrect tire pressure, improper wheel alignment,
out−of balance wheels, or severe braking.
Before storing radial, snow or studded tires, mark the
direction of rotation and be sure to install them in the
same direction when using them again. Tires should
be stored in a cool dry place.
Initial adjustment of the tire pressure warning
system is necessary after you have rotated your
tires. See “Tire pressure warning system” on page
462.

CHASSIS
585
CHECKING AND REPLACING TIRES
When to replace your tires
1New tread2Tread wear indicator
3Worn tread
Replace the tires when the tread wear indicators
show. The location of tread wear indicators is
shown by the marks such as “TWI” or “
Δ” marks,
etc., molded on the sidewall of each tire. 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.
The effectiveness of snow tires is lost if the tread
wears down below 4 mm (0.16 in.).
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 air loss occurs while driving, do not continue driving.
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.

CHASSIS
586
This applies also to the spare tire and tires stored
for future use.
Tire selection
When replacing a tire, use a tire of the same size
and construction, and the same or greater
maximum load as the originally installed tires.
Also, on fourwheel drive models, all the tires
must be the same brand and have the same tread
patterns.
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.
Check that the maximum load of the replaced tire is
greater than 1/2 of the Gross Axle Weight Ratings
(GAWR) of either the front axle or the rear axle,
whichever is greater. As for the maximum load of
the tire, see the load limit at maximum cold tire
inflation pressure mentioned on the sidewall of the tire,
and as for the Gross Axle Weight Ratings (GAWR),
see the Certification Label. For details about
Certification Label and sidewall of the tire, see pages
536 and 573.
CAUTION
Observe the following instructions. Otherwise,
an accident may occur resulting in death or
serious injuries.
Do not mix radial, bias belted, or biasply tires
on your vehicle, as this may cause dangerous
handling characteristics resulting in loss of
control.
 Do not use tires other than the manufacturer’s
recommended size, as this may cause
dangerous handling characteristics resulting
in loss of control.
 Fourwheel drive models:
Do not use tires of different brands, sizes,
construction or tread patterns, as this may
cause dangerous handling characteristics
resulting in loss of control.

CHASSIS
587
INSTALLING SNOW TIRES ANDCHAINS
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 tires of the same size,
construction and load capacity as the originally installed
tires. Also, on fourwheel drive models, all the tires must
be the same brand and have the same tread patterns.
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.
CAUTION
Observe the following instructions. Otherwise, an
accident may occur resulting in death or serious
injuries.
Do not use snow tires other than the manufacturer’s
recommended size, as this may cause dangerous
handling characteristics resulting in loss of control.
 Fourwheel drive models:
Do not use snow tires of different brands, sizes,
construction or tread patterns, as this may cause
dangerous handling characteristics resulting in loss
of control.

CHASSIS
588
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
1Side chain2Cross chain
Use the tire chains of correct size.
For 225/65R17 101S or P235/55R18 99V tires, use the
following type chains. mm (in.)
A: Diameter of side chain 3.0 (0.12)
B: Width of side chain 10.0 (0.39)
C: Length of side chain 30.0 (1.18)
D: Width of cross chain 14.0 (0.55)
E: Length of cross chain 25.0 (0.98)
F: Diameter of cross chain 4.0 (0.16)

CHASSIS
589
Regulations regarding the use of tire chains vary
according to location or type of road. Always check local
regulations before installing chains.
NOTICE
If the wrong combination of tire and chain is used, the
chains could damage the vehicle body.
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 lockedwheel braking, as use of
chains may adversely affect vehicle handling.
 When driving with chains installed, be sure to drive
carefully. Slow down before entering curves to avoid
losing control of the vehicle. Otherwise an accident
may occur.
 Vehicles with electronically modulated air
suspension: When installing the tire chains, be sure
to turn off the height control and stop the engine.
Otherwise, the vehicle height may change in the
automatic leveling function, resulting in an
unexpected accident. For details, see page 446.
If the chains are installed, the tire pressure warning
system may not operate properly. See “Tire pressure
warning system” on page 462.