2018 LEXUS RX450h tire size

3914-6. Driving tips
4
Driving
RX450h_RX450hL _U_OM48F85UAccelerate the vehicle slowly, keep a sa fe distance between you and the vehicle
ahead, and drive at a reduced spee d suitable to road conditions.●
Park the vehicle and move the shift lever to P without setting the parking
brake. The parking brake may freeze up, preventing it from being released. If
the vehicle is parked without setting the parking brake, make sure to block the
wheels.
Failure to do so may be dangerous because it may cause the vehicle to move
unexpectedly, possibly leading to an accident. When the parking brake is in automatic mo de, release the parkin g brake after shifting
the shift lever to P. ( → P. 253)●
If the vehicle is parked without setting the parking brake, confirm that the shift
lever cannot be moved out of P
* .
* : The shift lever will be locked if it is atte mpted to be shifted from P to any other posi-
tion without depressing the brake pedal. If the shift lever can be shifted from P, there
may be a problem with the shift lock sy stem. Have the vehicle inspected by your
Lexus dealer immediately.
Use the correct tire chain size when mounti ng the tire chains. Chain size is regu-
lated for each tire size.
Side chain:
0.12 in. (3 mm) in diameter
0.43 in. (10.8 mm) in width
0.98 in. (25 mm) in length
Cross chain:
0.15 in. (3.9 mm) in diameter
0.54 in. (13.8 mm) in width
1.00 in. (25.3 mm) in length
Regulations regarding the use of tire chains vary depending on location and type
of road. Always check local regu lations before installing chains.When driving the vehicle
When parking the vehicle
Selecting tire chains 1
2
3
4
5
6
Regulations on the use of tire chains

392 4-6. Driving tips
RX450h_RX450hL _U_OM48F85UTo enable the windshield wi pers to be lifted when he avy snow or icy conditions
are expected, change the rest position of the windshield wipers from the
retracted position below the hood to th e service position using the wiper lever.
( →
P. 270) ■
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 driving
1/4 - 1/2 mile (0.5 - 1.0 km). ●
Install tire chains following the instru ctions provided with the tire chains. Windshield wipers
WARNING ■
Driving with snow tires
Observe the following precautions to reduce the risk of accidents.
Failure to do so may result in a loss of vehi cle control and cause death or serious injury.●
Use tires of the specified size. ●
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 dr iven 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 acceleration, abrupt steering, sudden braking and shifting operations
that cause sudden engine braking. ●
Slow down sufficiently before entering a cu rve to ensure that vehicle control is main-
tained. ●
Do not use the LKA (Lane-Keeping Assist) system.

612 7-3. Do-it-yourself maintenance
RX450h_RX450hL _U_OM48F85UYour vehicle is equipped with a tire pressure warning system that uses tire pres-
sure warning valves and transmitters to detect low tire inflation pressure before
serious problems arise.
◆ Installing tire pressure warning valves and transmitters
When replacing tires or wheels, tire pr essure warning valv es and transmitters
must also be installed.
When new tire pressure wa rning valves and transmitters are installed, new ID
codes must be registered in the tire pressure warning computer and the tire
pressure warning system must be initia lized. Have tire pressure warning valve
and transmitter ID codes registered by your Lexus dealer. ( → P. 613)
◆ Initializing the tire pressure warning system ■
The tire pressure warning system must be initialized in the following circum-
stances: ●
When the tire inflation pressure is changed such as when changing travel-
ing speed. ●
When the tire inflation pressure is changed such as when the tire size is
changed. ●
When rotating the tires
When the tire pressure warning system is initialized, the current tire inflation
pressure is set as the benchmark pressure.Tire pressure warning system ●
The tire pressure detected by the tire
pressure warning system can be dis-
played on the multi-information display. The illustration used is intended as an exam-
ple, and may differ from the image that is
actually displayed on the multi-information
display.●
If the tire pressure drops below a prede-
termined level, the driver is warned by a
screen display and a warning light.
( → P. 662) The illustration used is intended as an exam-
ple, and may differ from the image that is
actually displayed on the multi-information
display.

614 7-3. Do-it-yourself maintenance
RX450h_RX450hL _U_OM48F85U■
When to replace your vehicle’s tires
Tires should be replaced if: ●
The treadwear indicators are showing on a tire. ●
You have tire damage such as cuts, splits, cracks deep enou gh 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 tire
pressure warning system will not work proper ly. After driving for about 20 minutes, the
tire pressure warning light blinks for 1 minu te and stays on to indicate a system malfunc-
tion. ■
Tire life
Any tire over 6 years old must be checked by a qualified technician even if it has seldom
or never been used or damage is not obvious.■
Proper storage of the spare tire (RX450hL)
As an improperly stored spare tire may cause damage to the wire cable that holds it,
check that the spare tire is stored properly on a daily basis.
If the spare tire is slanted, the hoist assemb ly may be stuck in the wheel opening. If the
spare tire rattles while driving, it may not be fully raised. Lower the spare tire to the
ground and make sure that the hoist assemb ly is perpendicular to the wheel opening.
Raise the tire slowly and steadily until a click is heard and the jack handle skips.
If the spare tire cannot be lowered, the wire cable may be severed. Have the vehicle
inspected at your Lexus dealer. ■
Routine tire inflation pressure checks
The tire pressure warning syst em does not replace routine tire inflation pressure checks.
Make sure to check tire inflat ion pressure as part of your routine of daily vehicle checks.●
If the stored spare tire appears to be slanted or
rattles while driving, the spare tire may not be
properly stored. Store the spare tire again by
performing the following tire change proce-
dure correctly: 1
2

6157-3. Do-it-yourself maintenance
7
Maintenance and care
RX450h_RX450hL _U_OM48F85U■
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, whichever is
greater.
■
Tire types ●
Summer tires
Summer tires are high-speed performance ti res 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 roads or icy road s, 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 adequate for
driving in most winter conditions as well as for use year-round. All season tires, how-
ever, do not have adequate traction perfor mance compared with snow tires in heavy
or loose snow. Also, all season tires fall short in acceleration and handling perfor-
mance 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 ti res of the same size, construction and load capacity as the
originally installed tires. Since your vehicle has radial tires as or iginal equipment, make
sure your snow tires also have radial cons truction. Do not install studded tires without
first checking local regulations for possible restrictions. Snow tires should be installed
on all wheels. ( → P. 390)■
Initializing the tire pressure warning system
Initialize the system with the tire inflation pressure adjusted to the specified level.■
If the tread on snow tires wears down below 0.16 in. (4 mm)
The effectiveness of the tire s as snow tires is lost.■
If you press the tire pressure warning reset switch accidentally
If initialization is performed, adjust the tire inflation pressure to the specified level and ini-
tialize the tire pressure warning system again. For the GAWR, see the Ce rtification Label. For
the maximum load of the tire, see the load limit
at maximum cold tire inflation pressure men-
tioned on the sidewall of the tire. ( → P. 723)

616 7-3. Do-it-yourself maintenance
RX450h_RX450hL _U_OM48F85U■
Situations in which the tire pressure warning system may not operate properly ●
In the following cases, the tire pressure warning system may not operate properly.
• If non-genuine Lexus wheels are used.
• A tire has been replaced with a tire that is not an OE (Original Equipment) tire.
• A tire has been replaced with a tire that is not of the specified size.
• Tire chains, etc. are equipped.
• If a window tint that affects th e radio wave signals is installed.
• If there is a lot of snow or ice on the vehi cle, particularly around the wheels or wheel
housings.
• If the tire inflation pressure is extr emely higher than the specified level.
• If wheel without the tire pressure warning valve and transmitter is used.
• If the ID code on the tire pressure warning valves and transmitters is not registered
in the tire pressure warning computer. ●
Performance may be affected in the following situations.
• Near a TV tower, electric power plant, gas station, radio station, large display, air-
port or other facility that generates st rong radio waves or electrical noise.
• When carrying a portable radio, cellular phone, cordless phon e or other wireless
communication device.
If tire position information is not correctl y displayed due to the radio wave conditions,
the display may be corrected by driving and changing the radio wave conditions. ●
When the vehicle is parked, the time taken for the warning to start or go off could be
extended. ●
When tire inflation pressure declines rapidly for example when a tire has burst, the
warning may not function. ■
The initialization operation ●
Make sure to carry out initialization afte r adjusting the tire inflation pressure.
Also, make sure the tires are cold before carryi ng out initialization or tire inflation pres-
sure adjustment. ●
If you have accidentally turned the power switch off during in itialization, it is not neces-
sary to press the reset switch again as initialization will re start automatically when the
power switch has been turned to ON mode for the next time. ●
If you accidentally press the re set switch when initialization is not necessary, adjust the
tire inflation pressure to the specified leve l when the tires are co ld, and conduct initial-
ization again. ●
While the position of each tire is being de termined and the inflation pressures are not
being displayed on the multi-info rmation display, if the inflat ion pressure of a tire drops,
the tire pressure warning light will come on.

6197-3. Do-it-yourself maintenance
7
Maintenance and care
RX450h_RX450hL _U_OM48F85UWARNING ■
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 han-
dling characteristics, which may lead to an accident resu lting in death or serious injury.●
Do not mix tires of different makes, models 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 (radial, bias-belted or bias-ply tires). ●
Do not mix summer, all season and snow tires. ●
Do not use tires that have be en used on another vehicle.
Do not use tires if you do not know how they were used previously. ●
Do not tow if your vehicle has a compact spare tire installed. ■
When initializing the tire pressure warning system
Do not initializing tire inflatio n pressure 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, tire pressure warning valv es, transmitters 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 trans-
mitters may be damaged if not handled correctly. ●
Make sure to install the tire valve caps. If the tire valve caps ar e not installed, water
could enter the tire pressure warning valves and the tire pressure warning valves
could be bound. ●
When replacing tire valve caps, do not use tire valve caps other than those specified.
The cap may become stuck. ■
To avoid damage to the tire pressu re warning valves and transmitters
When a tire is repaired with liquid sealants, the tire pressure warning valve and trans-
mitter may not operate properly. If a liquid sealant is used, contact your Lexus dealer or
other qualified service shop as soon as possi ble. Make sure to replace the tire pressure
warning valve and transmitter when replacing the tire. ( → P. 612)■
Driving on rough roads
Take particular care when driving on roads with loose surfaces or potholes.
These conditions may cause lo sses in tire inflation pre ssure, reducing the cushioning
ability of the tires. In addition, driving on rough roads may cause damage to the tires
themselves, as well as the vehicle’s wheels and body. ■
If tire inflation pressure of ea ch tire becomes low while driving
Do not continue driving, or your tires and/or wheels may be ruined.

620 7-3. Do-it-yourself maintenance
RX450h_RX450hL _U_OM48F85UThe recommended cold tire inflation
pressure and tire size are displayed on
the tire and loading information label.
( → P. 717)
Tire inflation pressure Tire inflation pressure