Page 468 of 573

4678-2. Steps to take in an emergency
8
When trouble arises
IS350/250_U (OM53758U)
(If equipped)
Indicates that the windows and the moon roof are not
fully closed (with the engine switch off, and the driver’s
door open)A buzzer also sounds.
Close all the windows and the moon roof.
Indicates a malfunction in the brake override system
A buzzer also sounds.
Have the vehicle inspected by your Lexus dealer.
Indicates that engine oil level is low
A buzzer also sounds.
Check the level of engine oil, and add if necessary.
Indicates a malfunction in:
• The automatic headlig ht leveling system; or
• The Automatic High Beam system (if equipped)
• The LED headlight system (if equipped)
A buzzer also sounds.
Have the vehicle inspected by your Lexus dealer.
Indicates that the accelerator and brake pedal are being
depressed simultaneously
Release the accelerator or brake pedal.
Indicates that the tire in flation pressure is low
Check the tire inflation pressure, and adjust to the
appropriate level.
Wa r n i n g m e s s a g eDetails/Actions
(Flashes)
(Flashes)
Page 484 of 573

4838-2. Steps to take in an emergency
8
When trouble arises
IS350/250_U (OM53758U)
■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 0 7 )
■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 ti re 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, th e 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
Page 508 of 573

5079-1. Specifications
9
Vehicle specifications
IS350/250_U (OM53758U)
Ty p e A
Ty p e B
Ty 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)
Page 509 of 573
5089-1. Specifications
IS350/250_U (OM53758U)
Ty p e D
Ty 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)
Page 515 of 573

5149-1. Specifications
IS350/250_U (OM53758U)
Ti r e s i z e ( P. 5 1 6 )
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. 4 1 5 )
An all season tire has “M+S” on the sidewall. A tire not marked “M+S” is a summer
tire.
Maximum cold tire inflation pressure ( P. 5 2 0 )
This means the pressure to which a tire may be inflated.
Load limit at maximum cold tire inflation pressure (P. 5 2 0 )
Tire ply composition and materials
Plies are layers of rubber-coated parallel co rds. 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. 5 1 5 )
Location of treadwear indicators (P. 4 1 1 )
“TEMPORARY USE ONLY”
A compact spare tire is identified by the phrase “TEMPORARY USE ONLY” molded
on its sidewall. This tire is design ed for temporary emergency use only.
1
2
3
4
5
6
7
8
9
10
11
Page 521 of 573

5209-1. Specifications
IS350/250_U (OM53758U)
Glossary of tire terminology
Tire related termMeaning
Cold tire inflation pressure
Tire pressure when the vehicle has been parked for
three hours or more, or has not been driven more than 1
mile or 1.5 km un der that condition
Maximum inflation pres-
sureThe maximum cold inflated pressure to which a tire may
be inflated, shown on the sidewall of the tire
Recommended inflation
pressureCold tire inflation pressure recommended by a manu-
facturer
Accessory weight
The combined weight (in excess of those standard items
which may be replaced) of automatic transmission,
power steering, power brakes, power windows, power
seats, radio and heater, to the extent that these items are
available as factory-installed equipment (whether
installed or not)
Curb weight
The weight of a motor vehicle with standard equipment,
including the maximum capacity of fuel, oil and coolant,
and if so equipped, air co nditioning and additional
weight optional engine
Maximum loaded vehicle
weight
The sum of:
(a) Curb weight
(b) Accessory weight
(c) Vehicle capacity weight
(d) Production options weight
Normal occupant weight150 lb. (68 kg) times the numb er of occupants specified
in the second column of Table 1* that follows
Occupant distributionDistribution of occupants in a vehicle as specified in the
third column of Table 1
* below
Production options weight
The combined weight of installed regular production
options weighing over 5 lb. (2.3 kg) in excess of the
standard items which they replace, not previously con-
sidered in curb weight or accessory weight, including
heavy duty brakes, ride levelers, roof rack, heavy duty
battery, and special trim
RimA metal support for a tire or a tire and tube assembly
upon which the tire beads are seated
Page 523 of 573

5229-1. Specifications
IS350/250_U (OM53758U)
CT
A pneumatic tire with an inverted flange tire and rim
system in which the rim is designed with rim flanges
pointed radially inward and the tire is designed to fit on
the underside of the rim in a manner that encloses the
rim flanges inside the air cavity of the tire
Extra load tireA tire designed to operate at higher loads and at higher
inflation pressures than the corresponding standard tire
GrooveThe space between two adjacent tread ribs
InnerlinerThe layer(s) forming the inside surface of a tubeless tire
that contains the inflating medium within the tire
Innerliner separationThe parting of the innerliner from cord material in the
carcass
Intended outboard sidewall
(a) The sidewall that contains a whitewall, bears white lettering, or bears manufacturer, brand, and/or
model name molding that is higher or deeper than
the same molding on the ot her sidewall of the tire,
or
(b) The outward facing sidewall of an asymmetrical tire that has a particular side that must always face out-
ward when mounted on a vehicle
Light truck (LT) tire
A tire designated by its manufacturer as primarily
intended for use on lightweight trucks or multipurpose
passenger vehicles
Load ratingThe maximum load that a tire is rated to carry for a given
inflation pressure
Maximum load ratingThe load rating for a tire at the maximum permissible
inflation pressure for that tire
Maximum permissible infla-
tion pressureThe maximum cold inflation pressure to which a tire may
be inflated
Measuring rimThe rim on which a tire is fitted for physical dimension
requirements
Open spliceAny parting at any junction of tread, sidewall, or inner-
liner that extends to cord material
Outer diameterThe overall diameter of an inflated new tire
Tire related termMeaning
Page 524 of 573

5239-1. Specifications
9
Vehicle specifications
IS350/250_U (OM53758U)
Overall widthThe linear distance between the exteriors of the side-
walls of an inflated tire, including elevations due to label-
ing, decorations, or pr otective bands or ribs
Passenger car tire
A tire intended for use on passenger cars, multipurpose
passenger vehicles, and trucks, that have a gross vehicle
weight rating (GVWR) of 10,000 lb. or less.
PlyA layer of rubber-coated parallel cords
Ply separationA parting of rubber compound between adjacent plies
Pneumatic tire
A mechanical device made of rubber, chemicals, fabric
and steel or other materials, that, when mounted on an
automotive wheel, provides the traction and contains
the gas or fluid that sustains the load
Radial ply tire
A pneumatic tire in which the ply cords that extend to
the beads are laid at substantially 90 degrees to the
centerline of the tread
Reinforced tire A tire designed to operate at higher loads and at higher
inflation pressures than the corresponding standard tire
Section width
The linear distance between the exteriors of the side-
walls of an inflated tire, excluding elevations due to
labeling, decoration, or protective bands
SidewallThat portion of a tire between the tread and bead
Sidewall separationThe parting of the rubber compound from the cord
material in the sidewall
Snow tire
A tire that attains a traction index equal to or greater
than 110, compared to the ASTM E-1136 Standard Ref-
erence Test Tire, when using the snow traction test as
described in ASTM F-1805-00, Standard Test Method
for Single Wheel Driving Tract ion in a Straight Line on
Snow-and Ice-Covered Surfaces, and which is marked
with an Alpine Symbol ( ) on at least one sidewall
Te s t r i mThe rim on which a tire is fitted for testing, and may be
any rim listed as appropriate for use with that tire
Tire related termMeaning