wheel size Lexus IS250C 2010 Do-It-Yourself Maintenance / LEXUS 2010 IS350C/250C OWNERS MANUAL (OM53A20U)

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1-3. Adjustable components (seats, mirrors, steering wheel)
■Pregnant women
■People suffering illness
Obtain medical advice and wear the seat belt in the proper way.
■Child seat belt usage
The seat belts of your vehicle are principally designed for persons of adult size.
●Use a child restraint system appropriate for the child, until the child becomes
large enough to properly wear the vehicle's seat belt. ( P. 116)
●When the child becomes large enough to properly wear the vehicle's seat belt,
follow the instructions on P. 65 regarding seat belt usage.
■Replacing the belt after the pretensioner has been activated
If the vehicle is involved in multiple collisions, the pretensioner will activate for the
first collision, but will not activate for the second or subsequent collisions.
■Seat belt extender
Obtain medical advice and wear the seat belt
in the proper way. ( P. 6 5 )
Women who are pregnant should position
the lap belt as low as possible over the hips in
the same manner as other occupants. Extend
the shoulder belt completely over the shoul-
der and position the belt across the chest.
Avoid belt contact over the rounding of the
abdominal area.
If the seat belt is not worn properly, not only a
pregnant woman, but also the fetus could suf-
fer death or serious injury as a result of sud-
den braking or a collision.
If your seat belts cann ot be fastened securely
because they are not long enough, a person-
alized seat belt extender is available from
your Lexus dealer free of charge.

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2-4. Using other driving systems
2
When driving
CAUTION
■TRAC may not operate effectively when
Directional control and power may not be achievable while driving on slippery road
surfaces, even if the TRAC system is operating.
Do not drive the vehicle in conditions where stability and power may be lost.
■When the VSC is activated
The slip indicator light flashes and a warning buzzer sounds. Always drive carefully.
Reckless driving may cause an accident. Ex ercise particular care when the indica-
tor light flashes and a buzzer sounds.
■When TRAC and VSC are off
Be especially careful and drive at a speed appropriate to the road conditions. As
these are systems to ensure vehicle stability and driving force, do not turn off TRAC
and VSC unless necessary.
■Replacing tires
Make sure that all tires are of the specified size, brand, tread pattern and total load
capacity. In addition, make sure that the tires are inflated to the recommended tire
pressure level.
The ABS and VSC systems will not function correctly if different tires are fitted on
the vehicle.
Contact your Lexus dealer for further info rmation when replacing tires or wheels.
■Handling of tires and suspension
Using tires with any kind of problem or modifying the suspension will affect the driv-
ing assist systems, and may cause the system to malfunction.

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2-5. Driving information
Winter driving tips
Carry out the necessary preparations and inspections before driving the
vehicle in winter. Always drive the vehicle in a manner appropriate to the
prevailing weather conditions.
■ Pre-winter preparations
●Use fluids that are appropria te to the prevailing outside tempera-
tures.
• Engine oil
• Engine coolant
• Washer fluid
● Have a service technician inspect the level and specific gravity of
battery electrolyte.
● Have the vehicle fitted with four snow tires or purchase a set of
tire chains for the rear tires.
Ensure that all tires are the specified size and the same brand, and that
chains match the size of the tires.
■ Before driving the vehicle
Perform the following according to the driving conditions.
● Do not try to forcibly open a w indow or move a wiper that is fro-
zen. Pour warm water over the frozen area to melt the ice. Wipe
away the water immediately to prevent it from freezing.
● To ensure proper operation of the climate control system fan,
remove any snow that has accumu lated on the air inlet vents in
front of the windshield.
● Remove any ice that has accumul ated on the vehicle chassis.
● Periodically check for and remove any excess ice or snow that
may have accumulated in the wheel well or on the brakes.

221
2-5. Driving information
2
When driving
Selecting tire chainsUse the correct tire chain size when mounting the tire chains. Chain size
is regulated for each tire sizes.
Side chain
(0.12 in. [3 mm] in diameter)
Cross chain
(0.16 in. [4 mm] in diameter)
Regulations on the use of tire chains
● Regulations regarding the use of tire chains vary according to location
and type of road. Always check local regulations before installing
chains.
● Install the chains on the rear tires.
● Retighten the chains after driving 1 /4  1 /2 mile (0.5  1.0 km).
■When driving the vehicle
Accelerate the vehicle slowly and dr ive at a reduced speed suitable
to road conditions.
■ When parking the vehicle (in the winter time or in the cold lati-
tudes)
Park the vehicle and move the shift lever to P (automatic transmis-
sion) or 1 or R (manual transmission) and block the wheel under the
vehicle without setting the parking brake. The parking brake may
freeze up, preventing it from being released. If necessary, block the
wheels to prevent inadvertent sliding or creeping.

222
2-5. Driving information
■Tire chain installation (17-inch tires only)
Observe the following precautions when installing and removing chains.
●Install and remove tire chains in a safe location.
●Install tire chains on the rear tires only. Do not install tire chains on front tires.
●Install the tire chains on rear tires as tightly as possible. Retighten chains after
driving 1 /4
 1/2 mile (0.5  1.0 km).
●Install tire chains following the instructions provided in the accompanying
instructions.
CAUTION
■Driving with snow tires
Observe the following precautions to reduce the risk of accidents.
Failing to do so may result in a loss of vehicle control and cause death or serious
injury.
●Use tires of the size specified for your vehicle.
●Maintain the recommended level of air pressure.
●Do not drive in excess of 75 mph (120 km/h ), regardless of the type of snow tires
being used.
●Use snow tires on all, not just some wheels.
■Driving with tire chains (17-inch tires only)
Observe the following precautions to reduce the risk of accidents.
Failing to do so may result in the vehicle being unable to be driven safely, and may
cause death or serious injury.
●Do not drive in excess of the speed limit specified for the tire chains being used,
or 30 mph (50 km/h), whichever is lower.
●Avoid driving on bumpy road surfaces or over potholes.
●Avoid sudden turns and braking, as use of chains may adversely affect vehicle
handling.
●Slow down sufficiently before entering a curve to ensure that vehicle control is
maintained.

413
4-3. Do-it-yourself maintenance
4
Maintenance and care
Directional tiresTire direction marks
The tire sidewalls are marked with
arrows indicating the rolling direc-
tion of the tire. If mounted on the
wrong side of the vehicle, direc-
tional tires will not perform prop-
erly.
Installing tire pressure warning valves and transmittersWhen replacing tires or wheels, tire pressure warning valves and trans-
mitters must also be installed.
When new tire pressure warning va lves and transmitters are installed,
new tire pressure warning valve and transmitter ID codes must be regis-
tered in the tire pressure warning computer and tire pressure warning
system must be initialized. Have tire pressure warning valve and transmit-
ter ID codes registered by your Lexus dealer. ( P. 4 1 5 )
Initializing the tire pressure warning system
■ The tire pressure warning system must be initialized in the following
circumstances:
●When changing the ti re inflation pressure by changing traveling
speed or load weight, etc.
● When changing the tire size.
When the tire pressure warning sy stem is initialized, the current tire
inflation pressure is set as the pressure benchmark.

417
4-3. Do-it-yourself maintenance
4
Maintenance and care
■When to replace your vehicle’s tires
Tires should be replaced if:
●You have tire damage such as cuts, splits, cracks deep enough to expose the
fabric or bulges indicating internal damage
●A tire goes flat repeatedly or cannot be properly repaired due to the size or
location of a cut or other damage
If you are not sure, consult with your Lexus dealer.
■Replacing tires and wheels
If the ID code of the tire pressure warn ing valve and transmitter is not registered,
the tire pressure warning system will not work properly. After driving for about 20
minutes, the tire pressure warning light comes on after blinking for 1 minute to indi-
cate a system malfunction.
■Tire life
Any tire over 6 years old must be checked by a qualified technician even if they
have seldom or never been used or damage is not obvious.
■If the tread wears down below 0.16 in. (4 mm) on snow tires
The effectiveness of snow tires is lost.
■Low profile tires
Generally, low profile tires will wear more rapidly and tire grip performance will be
reduced on snowy and/or icy roads when co mpared to standard tires. Be sure to
use snow tires or tire chains
* on snowy and/or icy roads and drive carefully at a
speed appropriate for road and weather conditions.
*: Tire chains cannot be mounted on 18-inch tires.

418
4-3. Do-it-yourself maintenance
■Maximum load of tire
Check that the maximum load of the replacement tire is greater than 1 /2 of the
Gross Axle Weight Ratings (GAWR) of either the front axle or the rear axle, which-
ever is greater.
■Tire types
1 Summer tires
Summer tires are high-speed performance tires best suited to highway driving
under dry conditions. Since summer tires do not have the same traction perfor-
mance as snow tires, summer tires are inadequate for driving on snow-covered
or icy roads. For driving on snow-covered roads or icy roads, the use of snow tires
is recommended. When 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 ade-
quate for driving in most winter conditions , as well as for use year round. All sea-
son tires, however, do not have adequa te traction performance compared with
snow tires in heavy or loos e snow. Also, all season tires fall short in acceleration
and handling performance compared with summer tires in highway driving.
3Snow tires
For driving on snow-covered roads or ic y roads, we recommend using snow tires.
If you need snow tires, select tires of the same size, construction and load capac-
ity as the originally installed tires. 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 loca l regulations for possible restriction.
Snow tires should be installed on all wheels. ( P. 2 2 0 )
■Initializing the tire pressure warning system
Initialize the tire pressure warning system with the tire inflation pressure adjusted to
the specified level.
For the GAWR, see the Certification Label.
For the maximum load of the tire, see the load
limit at maximum cold tire inflation pressure
mentioned on the sidewall of the tire.
(
P. 5 5 1 )

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4-3. Do-it-yourself maintenance
CAUTION
■Tire pressure warning system operation
The tire pressure warning system may not provide warning immediately if a tire
bursts or if sudden air leakage occurs.
■When inspecting or replacing tires
Observe the following precautions to prevent accidents. Failure to do so may cause
damage to parts of the drive train, as well as dangerous handling characteristics,
which may lead to an accident resulting in death or serious injury.
●Do not mix tires of different makes, mode ls or tread patterns. Also, do not mix
tires of remarkably different treadwear.
●Do not use tire sizes other than those recommended by Lexus.
●Do not mix differently constructed tires (r adial, bias-belted or bias-ply tires).
●Do not mix summer, all season and winter tires.
●Do not use tires that have been used on another vehicle.
Do not use tires if you do not know how they were used previously.
■When initializing the tire pressure warning system
Do not press the satellite switch without fi rst adjusting the tire inflation pressure to
the specified level. Otherwise, the tire pressure warning light may not come on
even if the tire inflation pressure is low, or it may come on when the tire inflation
pressure is actually normal.
NOTICE
■Repairing or replacing tires, wheels, tire pressure warning valves and transmit-
ters and tire valve caps
●When removing or fitting the wheels, tires or the tire pressure warning valves and
transmitters, contact your Lexus dealer as the tire pressure warning valves and
transmitters may be damage d if not handled correctly.
●When replacing tire valve caps, do not us e tire valve caps other than those speci-
fied. The cap may become stuck.

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4-3. Do-it-yourself maintenance
Wheels
■When replacing wheels
The wheels of your Lexus are equipped with tire pressure warning valves and trans-
mitters that allow the tire pressure warning system to provide advanced warning in
the event of a loss in tire inflation pressure. Whenever wheels are replaced, the tire
pressure warning valves and transmitters must be installed. ( P. 4 1 3 )
If a wheel is bent, cracked or heavily corroded, it should be replaced. Oth-
erwise, the tire may separate from the wheel or cause loss of handling con-
trol.
■ Wheel selection
When replacing wheels, care should be taken to ensure that they
are equivalent to those removed in load capacity, diameter, rim
width, and inset
*.
Replacement wheels are available at your Lexus dealer.
*: Conventionally referred to as “offset”.
Lexus does not recommend using:
● Wheels of different sizes or types
● Used wheels
● Bent wheels that have been straightened
■ Aluminum wheel precautions
●Use only Lexus wheel nuts and wrenches designed for use with
your aluminum wheels.
● When rotating, repairing or changi ng your tires, check that the
wheel nuts are still tight after driving 1000 miles (1600 km).
● Be careful not to damage the aluminum wheels when using tire
chains.
● Use only Lexus genuine balance weights or equivalent and a
plastic or rubber hammer when balancing your wheels.