tire size Lexus IS250 2015 User Guide

4307-3. Do-it-yourself maintenance
IS350/250_U (OM53C50U)
CAUTION
■When inspecting or replacing tires
Observe the following precautions to prevent accidents.
Failure to do so may cause damage to parts of the drivetrain as well as dangerous han-
dling characteristics, which may lead to an a ccident resulting 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 been 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 operate the tire pressure warning reset 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 pressu re is low, or it may come on when the tire
inflation pressure is actually normal.
■Caution regarding interference with electronic devices
●Users of any electrical medical device other than implantable cardiac pacemakers,
cardiac resynchronization therapy-pacemakers or implantable cardioverter defibril-
lators should consult the manufacturer of the device for information about its opera-
tion under the influence of radio waves.
Radio waves could have unexpected effects on the operation of such medical
devices.
●People with implantable cardiac pacemakers,
cardiac resynchronization therapy-pacemak-
ers or implantable cardioverter defibrillators
should not come within 17.7 in. (450 mm) of
the tire pressure warning system initiators.
The radio waves may affect the operation of
such devices.

4327-3. Do-it-yourself maintenance
IS350/250_U (OM53C50U)
The recommended cold tire inflation
pressure and tire size are displayed on
the tire and loading information label.
( → P. 5 1 9 )
Tire inflation pressure
Tire inflation pressure

4357-3. Do-it-yourself maintenance
7
Maintenance and care
IS350/250_U (OM53C50U)
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 the following:
●Wheels of different sizes or types
●Used wheels
●Bent wheels that have been straightened
●Use only Lexus wheel nuts and wrenches designed for use with your alumi-
num wheels.
●When rotating, repairing or changing 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.
■When replacing wheels
The wheels of your vehicle are equipped with tire pressure warning valves and transmit-
ters 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 2 4 )
Wheels
If a wheel is bent, cracked or heavily corroded, it should be replaced. Other-
wise, the tire may separate from the wheel or cause a loss of handling control.
Wheel selection
Aluminum wheel precautions

4718-2. Steps to take in an emergency
8
When trouble arises
IS350/250_U (OM53C50U)
CAUTION
■Maintenance of the tires
Each tire, including the spare (if provided), should be checked monthly when cold and
inflated to the inflation pressure recommended by the vehicle manufacturer on the
vehicle placard or tire inflation pressure label (tire and load information label). (If your
vehicle has tires of a different size than the size indicated on the vehicle placard or tire
inflation pressure label [tire and load in formation label], you should determine the
proper tire inflation pressure for those tires.)
As an added safety feature, your vehicle has been equipped with a tire pressure moni-
toring system (TPMS-tire pressure warning system) that illuminates a low tire pressure
telltale (tire pressure warning light) when on e or more of your tires is significantly
under-inflated. Accordingly, when the low ti re pressure telltale (tire pressure warning
light) illuminates, you should stop and check yo ur tires as soon as possible, and inflate
them to the proper pressure. Driving on a significantly under-inflated tire causes the
tire to overheat and can lead to tire failure. Under-inflation also reduces fuel efficiency
and tire tread life, and may affect the vehicle’s handling and stopping ability.
Please note that the TPMS (tire pressure warning system) is not a substitute for proper
tire maintenance, and it is the driver’s responsibility to maintain correct tire pressure,
even if under-inflation has not reached the level to trigger illumination of the TPMS low
tire pressure telltale (tire pressure warning light).
Your vehicle has also been equipped with a TPMS (tire pressure warning system) mal-
function indicator to indicate when the system is not operating properly. The TPMS
(tire pressure warning system) malfunction indicator is combined with the low tire pres-
sure telltale (tire pressure warning light). When the system detects a malfunction, the
telltale will flash for approximately one minu te and then remain continuously illumi-
nated. This sequence will continue upon su bsequent vehicle start-ups as long as the
malfunction exists. When the malfunction indicator is illuminated, the system may not
be able to detect or signal low tire pressure as intended.
TPMS (tire pressure warning system) malfun ctions may occur for a variety of reasons,
including the installation of replacement or alternate tires or wheels on the vehicle that
prevent the TPMS (tire pressure warning system) from functioning properly. Always
check the TPMS (tire pressure warning syst em) malfunction telltale after replacing one
or more tires or wheels on your vehicle to ensure that the replacement or alternate
tires and wheels allow the TPMS (tire pressure warning system) to continue to function
properly.
NOTICE
■To ensure the tire pressure warning system operates properly
Do not install tires with different specificatio ns or makers, as the tire pressure warning
system may not operate properly.

4948-2. Steps to take in an emergency
IS350/250_U (OM53C50U)
■The compact spare tire
●The compact spare tire is identified by the label “TEMPORARY USE ONLY” on the
tire sidewall.
Use the compact spare tire temporarily, and only in an emergency.
●Make sure to check the tire inflation pressure of the compact spare tire.
(→ P. 5 1 9 )
■When using the compact spare tire
As the compact spare tire is not equipped with a tire pressure warning valve and trans-
mitter, low inflation pressure of the spare tire will not be indicated by the tire pressure
warning system. Also, if you replace the compact spare tire after the tire pressure warn-
ing light comes on, the light remains on.
■When the compact spare tire is equipped
The vehicle becomes lower when driving with the compact spare tire compared to when
driving with standard tires.
■If you have a flat rear tire on a road covered with snow or ice (vehicles with front and
rear tires of the same size)
Install the compact spare tire on one of the front wheels of the vehicle. Perform the fol-
lowing steps and fit tire chains to the rear tires:
Replace a front tire with the compact spare tire.
Replace the flat rear tire with the tire removed from the front of the vehicle.
Fit tire chains to the rear tires.
1
2
3

5199-1. Specifications
9
Vehicle specifications
IS350/250_U (OM53C50U)
XTy p e A
XTy p e B
XTy p e C
Tires and wheels
Ti r e s i z e205/55R16 91W, T125/70D17 98M (spare)
Tire inflation pressure
(Recommended cold tire
inflation pressure)
Front tire 36 psi (250 kPa, 2.5 kgf/cm2 or bar)
Rear tire 36 psi (250 kPa, 2.5 kgf/cm
2 or bar)
Spare tire
60 psi (420 kPa, 4.2 kgf/cm
2 or bar)
Wheel size16 × 7J, 17 × 4T (spare)
Wheel nut torque76 f t•lbf (103 N•m, 10.5 kgf•m)
Ti r e s i z e225/45R17 91W, T125/70D17 98M (spare)
Tire inflation pressure
(Recommended cold tire
inflation pressure)
Front tire
36 psi (250 kPa, 2.5 kgf/cm2 or bar)
Rear tire 36 psi (250 kPa, 2.5 kgf/cm
2 or bar)
Spare tire
60 psi (420 kPa, 4.2 kgf/cm
2 or bar)
Wheel size17 × 7 1 /2J, 17 × 4T (spare)
Wheel nut torque76 f t•lbf (103 N•m, 10.5 kgf•m)
Ti r e s i z e225/45R17 91V, T125/70D17 98M (spare)
Tire inflation pressure
(Recommended cold tire
inflation pressure)
Front tire
36 psi (250 kPa, 2.5 kgf/cm2 or bar)
Rear tire 36 psi (250 kPa, 2.5 kgf/cm
2 or bar)
Spare tire
60 psi (420 kPa, 4.2 kgf/cm
2 or bar)
Wheel size17 × 7 1 /2J, 17 × 4T (spare)
Wheel nut torque76 f t•lbf (103 N•m, 10.5 kgf•m)

5209-1. Specifications
IS350/250_U (OM53C50U)
XTy p e D
XTy p e E
Ti r e s i z e225/40R18 88Y, 255/35R18 90Y,
T125/70D17 98M (spare)
Tire inflation pressure
(Recommended cold tire
inflation pressure)
Front tire 36 psi (250 kPa, 2.5 kgf/cm2 or bar)
Rear tire 36 psi (250 kPa, 2.5 kgf/cm
2 or bar)
Spare tire 60 psi (420 kPa, 4.2 kgf/cm
2 or bar)
Wheel size18 × 8J (225/40R18), 18 × 8 1 /2J (255/35R18),
17 × 4T (spare)
Wheel nut torque76 f t•lbf (103 N•m, 10.5 kgf•m)
Ti r e s i z e225/40R18 88W, 255/35R18 90W,
T125/70D17 98M (spare)
Tire inflation pressure
(Recommended cold tire
inflation pressure)
Front tire
36 psi (250 kPa, 2.5 kgf/cm2 or bar)
Rear tire 36 psi (250 kPa, 2.5 kgf/cm
2 or bar)
Spare tire
60 psi (420 kPa, 4.2 kgf/cm
2 or bar)
Wheel size18 × 8J (225/40R18), 18 × 8 1 /2J (255/35R18),
17 × 4T (spare)
Wheel nut torque76 f t•lbf (103 N•m, 10.5 kgf•m)

5259-1. Specifications
9
Vehicle specifications
IS350/250_U (OM53C50U)
XFull-size tire
XCompact spare tire
Tire information
Ty p i c a l t i r e s y m b o l s

5289-1. Specifications
IS350/250_U (OM53C50U)
■Typical tire size information
The illustration indicates typical tire
size. Tire use (P = Passenger car,
T = Temporary use)
Section width (millimeters)
Aspect ratio
(tire height to section width)
Tire construction code
(R = Radial, D = Diagonal)
Wheel diameter (inches)
Load index
(2 digits or 3 digits)
Speed symbol
(alphabet with one letter)
■Tire dimensions
Section width
Tire height
Wheel diameter
Ti re si ze
1
2
3
4
5
6
7
1
2
3

5339-1. Specifications
9
Vehicle specifications
IS350/250_U (OM53C50U)
Rim diameter
(Wheel diameter)Nominal diameter of the bead seat
Rim size designationRim diameter and width
Rim type designationThe industry manufacturer’s designation for a rim by
style or code
Rim widthNominal distance between rim flanges
Vehicle capacity weight
(Total load capacity)The rated cargo and luggage load plus 150 lb. (68 kg)
times the vehicle’s designated seating capacity
Vehicle maximum load on
the tireThe load on an individual tire that is determined by dis-
tributing to each 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 dis-
tributing to each axle its share of curb weight, accessory
weight, and normal occupant weight (distributed in
accordance with Table 1
* below), and dividing by two
We a t h e r s i d eThe surface area of the rim not covered by the inflated
tire
BeadThe part of the tire that is made of steel wires, wrapped
or reinforced by ply cords and that is shaped to fit the
rim
Bead separationA breakdown of the bond between components in the
bead
Bias ply tireA pneumatic tire in which the ply cords that extend to
the beads are laid at alternate angles substantially less
than 90 degrees to the centerline of the tread
CarcassThe tire structure, except tread and sidewall rubber
which, when inflated, bears the load
ChunkingThe breaking away of pieces of the tread or sidewall
CordThe strands forming the plies in the tire
Cord separationThe parting of cords from adjacent rubber compounds
CrackingAny parting within the tread, sidewall, or innerliner of
the tire extending to cord material
Tire related termMeaning