2018 Lexus IS300 tire size

5278-2. Steps to take in an emergency
8
When trouble arises
IS350 AWD/IS350/IS300 AWD/IS300_U(OM53E34U)
WARNING
■Maintenance of the tires
Each tire, including the spare (if provided), should be checked monthly when cold and
inflated to the inflation pressure recomm ended 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 ha s 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 your tires as soon as possible, and inflate
them to the proper pressure. Driving on a si gnificantly 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 wa rning system) is not a substitute for proper
tire maintenance, and it is th e driver’s responsibility to ma intain correct tire pressure,
even if under-inflation has not reached the le vel to trigger illumination of the TPMS low
tire pressure telltale (tir e 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 indi cator 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 mi nute and then remain continuously illumi-
nated. This sequence will cont inue upon subsequent vehicle start-ups as long as the
malfunction exists. When the malfunction in dicator 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 system) 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 pressu re warning system) to continue to function
properly.

5648-2. Steps to take in an emergency
IS350 AWD/IS350/IS300 AWD/IS300_U(OM53E34U)
■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 tempor arily, and only in an emergency.
●Make sure to check the tire inflation pressure of the compact spare tire.
( → P. 593)
■When using the compact spare tire
As the compact spare tire is not equipped wi th 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

5939-1. Specifications
9
Vehicle specifications
IS350 AWD/IS350/IS300 AWD/IS300_U(OM53E34U)
Type A
Type B
Tires and wheels
Tire size225/45R17 91W, T125/70D17 98M (spare)
Tire inflation pressure
(Recommended cold tire
inflation pressure)
Front:
36 psi (250 kPa, 2.5 kgf/cm2 or bar)
Rear: 36 psi (250 kPa, 2.5 kgf/cm
2 or bar)
Spare: 60 psi (420 kPa, 4.2 kgf/cm
2 or bar)
Driving at high speeds (above 118 mph [190 km/h]) (in
countries where such speeds are permitted by law)
Add 5 psi (30 kPa, 0.3 kgf/cm
2 or bar) to the front
tires and rear tires. Never exceed the maximum cold
tire inflation pressure indi cated on the tire sidewall.
Wheel size17 × 7 1/2J, 17 × 4T (spare)
Wheel nut torque76 ft•lbf (103 N•m, 10.5 kgf•m)
Tire size225/45R17 91V, T125/70D17 98M (spare)
Tire inflation pressure
(Recommended cold tire
inflation pressure)
Front:
36 psi (250 kPa, 2.5 kgf/cm2 or bar)
Rear: 36 psi (250 kPa, 2.5 kgf/cm
2 or bar)
Spare: 60 psi (420 kPa, 4.2 kgf/cm
2 or bar)
Driving at high speeds (above 100 mph [160 km/h]) (in
countries where such speeds are permitted by law)
Add 5 psi (30 kPa, 0.3 kgf/cm
2 or bar) to the front
tires and rear tires. Never exceed the maximum cold
tire inflation pressure indi cated on the tire sidewall.
Wheel size17 × 7 1/2J, 17 × 4T (spare)
Wheel nut torque76 ft•lbf (103 N•m, 10.5 kgf•m)

5949-1. Specifications
IS350 AWD/IS350/IS300 AWD/IS300_U(OM53E34U)
Type C
Type D
Tire size225/40R18 88Y, 255/35R18 90Y,
T125/70D17 98M (spare)
Tire inflation pressure
(Recommended cold tire
inflation pressure)
Front:
36 psi (250 kPa, 2.5 kgf/cm2 or bar)
Rear:
36 psi (250 kPa, 2.5 kgf/cm
2 or bar)
Spare: 60 psi (420 kPa, 4.2 kgf/cm
2 or bar)
Driving at high speeds (above 137 mph [220 km/h]) (in
countries where such speeds are permitted by law)
Add 2 psi (10 kPa, 0.1 kgf/cm
2 or bar) to the front tires
and rear tires. Never exce ed the maximum cold tire
inflation pressure indicated on the tire sidewall.
Wheel size18 × 8J (225/40R18), 18 × 8 1/2J (255/35R18),
17 × 4T (spare)
Wheel nut torque76 ft•lbf (103 N•m, 10.5 kgf•m)
Tire size225/40R18 88W, 255/35R18 90W,
T125/70D17 98M (spare)
Tire inflation pressure
(Recommended cold tire
inflation pressure)
Front:
36 psi (250 kPa, 2.5 kgf/cm2 or bar)
Rear: 36 psi (250 kPa, 2.5 kgf/cm
2 or bar)
Spare: 60 psi (420 kPa, 4.2 kgf/cm
2 or bar)
Driving at high speeds (above 118 mph [190 km/h]) (in
countries where such speeds are permitted by law)
Add 6 psi (40 kPa, 0.4 kgf/cm
2 or bar) to the front
tires and rear tires. Never exceed the maximum cold
tire inflation pressure indi cated on the tire sidewall.
Wheel size18 × 8J (225/40R18), 18 × 8 1/2J (255/35R18),
17 × 4T (spare)
Wheel nut torque76 ft•lbf (103 N•m, 10.5 kgf•m)

5999-1. Specifications
9
Vehicle specifications
IS350 AWD/IS350/IS300 AWD/IS300_U(OM53E34U)
Full-size tire
Compact spare tire
Tire information
Typical tire symbols

6009-1. Specifications
IS350 AWD/IS350/IS300 AWD/IS300_U(OM53E34U)
Tire size (→ P. 602)
TUBELESS or TUBE TYPE
A tubeless tire does not have a tube and air is directly put into the tire. A tube type tire
has a tube inside the tire and the tube maintains the air pressure.
Radial tires or bias-ply tires
A radial tire has “RADIAL” on the sidewall. A tire not marked “RADIAL” is a bias-ply
tire.
Summer tires or all season tires (→ P. 487)
An all season tire has “M+S” on the side wall. A tire not marked “M+S” is a summer
tire.
Maximum cold tire inflation pressure (→ P. 606)
This means the pressure to which a tire may be inflated.
Load limit at maximum cold tire inflation pressure (→ P. 606)
Tire ply composition and materials
Plies are layers of rubber-c oated parallel cords. Cords are the strands which form the
plies in a tire.
Uniform tire quality grading
For details, see “Uniform Tire Quality Grading” that follows.
DOT and Tire Identification Number (TIN) (→ P. 601)
Location of trea dwear indicators (→ P. 483)
“TEMPORARY USE ONLY”
A compact spare tire is identified by the phrase “TEMPORARY USE ONLY” molded
on its sidewall. This tire is designed for temporary emergency use only.
1
2
3
4
5
6
7
8
9
10
11

6019-1. Specifications
9
Vehicle specifications
IS350 AWD/IS350/IS300 AWD/IS300_U(OM53E34U)
DOT symbol*
Tire Identification Number (TIN)
Tire manufacturer’s identification mark
Tire size code
Manufacturer’s optional tire type code (3 or 4 letters)
Manufacturing week
Manufacturing year
Manufacturer’s code
*: The DOT symbol certifies that the tire co nforms to applicable Federal Motor Vehicle
Safety Standards.
Typical DOT and Tire Identification Number (TIN)
Type AType B
1
2
3
4
5
6
7
8

6029-1. Specifications
IS350 AWD/IS350/IS300 AWD/IS300_U(OM53E34U)
■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
Tire size
1
2
3
4
5
6
7
1
2
3