2012 Lexus IS250 tire size

535
6-1. Specifications
6
Vehicle specifications
IS350/250_UTy p e E
■ Compact spare tire
Ti r e s i z eFront tires: 225/40R18 88W
Rear tires: 255/40R18 95W
Front and rear tire inflation pres-
sure
(Recommended cold tire inflation
pressure)
Driving under normal conditions
Front:
35 psi (240 kPa, 2.4 kgf/cm
2 or bar)*
Rear:
38 psi (260 kPa, 2.6 kgf/cm
2 or bar)*
*: When driving at high speeds above 100 mph
(160 km/h), in countries where such speeds are
permitted by law, add 7.2 psi (50 kPa, 0.5 kgf/
cm
2 or bar) to the front tires and rear tires.
Never exceed the maximum cold tire inflation
pressure indicated on the tire sidewall.
Wheel sizeFront wheels: 18 × 8J
Rear wheels: 18 × 8 1 /2J
Wheel nut torque76 ft•lbf (103 N•m, 10.5 kgf•m)
Ti r e s i z e
Ty p e A
T125/70D17 98M
Ty p e B
T145/70D17 106M
Tire inflation pressure
(Recommended cold tire inflation
pressure)
60 psi (420 kPa, 4.2 kgf/cm2 or bar)
Wheel size17 × 4T

541
6-1. Specifications
6
Vehicle specifications
IS350/250_U
Tire information
Ty p i c a l t i r e s y m b o l s
Standard tire
Compact spare tire
Tire size (→P. 543)
DOT and Tire Identification Number (TIN) (→ P. 543)
Location of treadwear indicators ( →P. 412)
Tire ply composition and materials
Plies are layers of rubber-coated parallel cords. Cords are the strands
which form the plies in a tire.

543
6-1. Specifications
6
Vehicle specifications
IS350/250_U
Typical DOT and tire identification number (TIN)DOT symbol
*
Tire Identification Number (TIN)
Tire manufacturer's identifica-
tion mark
Tire size code
Manufacturer's optional tire
type code (3 or 4 letters)
Manufacturing week
Manufacturing year
*: The DOT symbol certifies thatthe tire conforms to applicable
Federal Motor Vehicle Safety
Standards.
Tire size
■ Typical tire si ze information
The illustration indicates typical
tire size.
Ti r e u s e
(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 or 3 digits)
Speed symbol
(alphabet with one letter)

547
6-1. Specifications
6
Vehicle specifications
IS350/250_U
Maximum inflation pres-
sureThe maximum cold inflated pressure to which a tire
may be inflated, shown on the sidewall of the tire
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 number of occupants speci-
fied in the second column of Table 1
* that follows
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
considered in curb weight or accessory weight,
including heavy duty brakes, ride levelers, roof rack,
heavy duty battery, and special trim
Vehicle capacity weight
(Total load capacity)The rated cargo and luggage load plus 150 lb. (68
kg) times the vehicle's designated seating capacity
Occupant distributionDistribution of occupants in a vehicle as specified in
the third column of Table 1
* below
Recommended inflation
pressureCold tire inflation pressure recommended by a man-
ufacturer.
RimA metal support for a tire or a tire and tube assembly
upon which the tire beads are seated
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
Tire related termMeaning

559
6
Vehicle specifications
IS350/250_U
6-3. Initialization
Items to initialize
ItemWhen to initializeReference
Maintenance data
(U.S.A. only)After the maintenance is performedP. 3 8 6
Tire pressure warning
system
• When rotating the tires with differing front and rear tire inflation pressures.
• When changing the tire inflation pressure by changing traveling
speed.
• When changing the tire size.
P. 4 1 3
The following items must be initialized for normal system operation in cases
such as after the battery is reconnected, or maintenance is performed on
the vehicle.

587
Alphabetical index
IS350/250_U
Tire informationGlossary ................................................ 546
Size ........................................................... 543
Tire identification number ............. 543
Uniform tire quality grading......... 544
Tires
Chains ..................................................... 206
Checking ................................................. 412
If you have a flat tire.......................... 492
Inflation pressure ................................424
Inflation pressure sensor.................. 414
Information..............................................541
Replacing............................................... 492
Rotating tires .......................................... 412
Size ............................................................. 531
Snow tires.............................................. 206
Tools ...........................................................492
Total load capacity............................... 205
Towing Dinghy towing............................... 211, 212
Emergency towing ........................... 463
Trailer towing......................................... 210
TRAC .......................................................... 196
Traction control ...................................... 196
Transmission shift switches ................ 149
Trip meter..................................................158 Trunk
Extending trunk space ....................354
Opener ...................................................... 52
Trunk light
Trunk light ................................................. 53
Wattage ................................................. 536
Turn signal lights Replacing light bulbs ......................... 451
Switch........................................................ 154
Wattage ................................................. 536
USB port* .................................................... 260
Vanity lights Vanity lights .......................................... 337
Wattage ................................................. 536
Vanity mirrors ........................................ 337
VDIM .......................................................... 196
Vehicle dynamics integrated management ........................................ 196
Vehicle identification number .......... 521
Vehicle stability control....................... 196
Ventilators ...............................................348
Voice command switch* ...................298
VSC............................................................. 196
U
V
*: For vehicles with a navigation system, refer to the “Navigation System Owner’s Manual”.