tire size Lexus HS250h 2010 Setup / LEXUS 2010 HS250H OWNERS MANUAL (OM75006U)

229
2-4. Using other driving systems
2
When driving
CAUTION
■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
inflation pressure level.
The ABS and VSC systems will not function correctly if different tires are installed
on the vehicle. 
Contact your Lexus dealer for further info rmation when replacing tires or wheels.
■Handling of tires and the suspension
Using tires with any kind of problem or modifying the suspension will affect the driv-
ing assist systems, and may cause a system to malfunction.

244
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 ar
e appropriate to the prevailing outside tempera -
tures.
• Engine oil
• Engine/power control unit coolant
• Washer fluid
● Ha
ve the vehicle fitted with four snow tires or purchase a set of
tire chains for the front tires.
Ensure that all tires are the same si ze and brand, and that chains match
the size of the tires.
■ Before driving the vehicle
Perform the following accord ing to the driving conditions:
● D
o not try to forcibly open a w indow or move a wiper that is fro-
zen. Pour warm water over the frozen ar
ea to melt the ice. Wipe
away the water immediately to prevent it from freezing.
● T
o ensure proper operation of the climate control system fan,
remove any snow that has accumulated on the air inlet vents in
front of the windshield.
● R
emove any ice that has accumul ated on the vehicle chassis.
● P
eriodically check for and remove any excess ice or snow that
may have accumulated in the wheel well or on the brakes.
■ When driving the v
ehicle
Accelerate the vehicle slowly and drive at a reduced speed suitable to the
road conditions.

245
2-5. Driving information
2
When driving
Selecting tire chains
Use the correct tire chain size when mounting the tire chains. Chain size
is regulated for each tire size.
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 depending on location
and type of road. Always check local regulations before installing chains.
■When parking the vehicle
Park the vehicle and push the P position switch and block the wheel
under the vehicle without setting the parking brake. The parking
brake may freeze up, preventing it from being released.
■Tire chain installation
Observe the following precautions when installing and removing chains:
●Install and remove tire chains in a safe location.
●Install tire chains on the front tires only. Do not install tire chains on the rear tires.
●Install tire chains on front tires as tightly as possible. Retighten chains after driv -
ing 1 /4 
1/2 mile (0.5  1.0 km).
●Install tire chains following the instru ctions provided with the tire chains.

246
2-5. Driving information
CAUTION
■Driving with snow tires
Observe the following precautions to reduce the risk of accidents. 
Failure to do so may result in a loss of vehicle control and cause death or serious
injury.
●Use tires of the size specified.
●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
Observe the following precautions to reduce the risk of accidents. 
Failure 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.
NOTICE
■Repairing or replacing snow tires
Request repairs or replacement of snow tire s from Lexus dealers or legitimate tire
retailers. 
This is because the removal and attachment of snow tires affects the operation of
the tire pressure warning valves and transmitters.
■Fitting tire chains
The tire pressure warning valves and transmitters may not function correctly when
tire chains are fitted.

438
4-3. Do-it-yourself maintenance
Installing tire pressure warning valves and transmitters
When replacing tires or wheels, tire pressure warning valves and trans-
mitters must also be installed.
When new tire pressure warning va lv
es and transmitters are installed,
new ID codes must be registered in the tire pressure warning computer
and the tire pressure warning system must be initialized. Have tire pres-
sure warning valve and transmitter ID codes r
egistered by your Lexus
dealer. ( P. 4 3 9 )
Initializing the tire pressure warning system
■The tire pressure warning system must be initialized in the following
circumstances:
● V
ehicles with P225/45R18 91W tires: When rotating front and rear
tires which have different tire inflation pressures
● When changing the tir
e size
When the tire pressure warning sys tem is initializ
ed, the current tire
inflation pressure is set as the benchmark pressure.

440
4-3. Do-it-yourself maintenance
■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, and 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 warning valve and transmitter is not registered,
the tir
e pressure warning system will not work properly. After driving for about 20
minutes, the tire pressure warning light flas hes for 1 minute and stays on to indicate a
system malfunction.
■Tire life
Any tire over 6 years old must be checked by a
qualified technician even if it has sel-
dom or never been used or damage is not obvious.
■Routine tire inflation pressure checks
The tire pressure warning system does not replace routine tire inflation pressure
ch
ecks. Make sure to check tire inflation pressure as part of your routine of daily
vehicle checks.
■Low profile tires (vehicles with P225/45R18 91W tires)
Generally, low profile tires will wear more rapidly and tire grip performance will be
r
educed 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.

441
4-3. Do-it-yourself maintenance
4
Maintenance and care
■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
●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 in adequate 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.
●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 adequate traction performance compared with
snow tires in heavy or loose snow. Also, al l season tires fall short in acceleration
and handling performance compared with summer tires in highway driving.
●Snow tires
For driving on snow-covered roads or icy 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 local regulations for possible restrictions.
Snow tires should be installed on all wheels. ( P. 2 4 4 )
■Initializing the tire pressure warning system
Initialize the system with the tire inflatio n pressure adjusted to the specified level.
■If the tread on snow tires wears down below 0.16 in. (4 mm)
The effectiveness of the tires as snow tires is lost.
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 6 0 )

443
4-3. Do-it-yourself maintenance
4
Maintenance and care
CAUTION
■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 resu lting 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 th an those recommended by Lexus.
●Do not mix differently constructed tires (radial, bias-belted or bias-ply tires).
●Do not mix summer, all season and snow 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 operate the tire pressure warning re set switch without first 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 and tire pressure warning valves and trans-
mitters
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.
■To avoid damaging the tire pressu re warning valves and transmitters
Do not use liquid sealants on flat tires.
■Driving on rough roads
Take particular care when driving on roads with loose surfaces or potholes. 
These conditions may cause losses in tire inflation pressure, reducing the cushion-
ing ability of the tires. In addition, driv ing on rough roads may cause damage to the
tires themselves, as well as the vehicle’s wheels and body.

445
4-3. Do-it-yourself maintenance
4
Maintenance and care
Tire inflation pressure
■Tire inflation pressure
The recommended cold tire inflation pressure and tire size are dis -
played on the tire and loading information label. ( P. 555)
■ Inspection and adjustment pr
ocedure
Ti r e v a l v e
Tire pressure gauge
Remove the tire valve cap.
Press the tip of the tire pressure gauge onto the tire valve.
Read the pressure using the gauge graduations.

448
4-3. Do-it-yourself maintenance
Wheels
■When replacing wheels
The wheels of your vehicle are equipped with tire pressure warning valves and
tr
ansmitters that allow the tire pressure warning system to provide advance warning
in the event of a loss in tire inflation pressure. Whenever wheels are replaced, tire
pressure warning valves and transmitters must be installed. ( P. 4 3 8 )
If a wheel is bent, cracked or heavily corroded, it should be replaced.
Otherwise, the tire may separate from the wheel or cause a loss of han
-
dling control.
■ Wheel selection
When replacing wheels, care should be taken to ensure that they
ar

e 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 the following:
● Wheels of dif
ferent sizes or types
● Used wheels
● Bent wheels that ha
ve been straightened
■ Aluminum wheel pr
ecautions
● Use only L
exus wheel nuts and wr enches designed for use with
your aluminum wheels.
● When r
otating, repairing or changi ng your tires, check that the
wheel nuts are still tight after driving 1000 miles (1600 km).
● Be car
eful not to damage the aluminum wheels when using tire
chains.
● Use only L
exus genuine balance weights or equivalent and a
plastic or rubber hammer when balancing your wheels.