tire size Lexus IS250 2008 User Guide

320
4-3. Do-it-yourself maintenance
08_IS350/250_U_(L/O_0708)
Wheels
■When replacing wheels
The wheels of your Lexus are equipped with tire pressure warning valves and trans-
mitters that allow the tire pressure warning system to provide advanced warning in
the event of a loss in tire inflation pressure. Whenever wheels are replaced, the tire
pressure warning valves and transmitters must be switched over from the old
wheels. (
→P. 3 0 8 )
If a wheel is bent, cracked or heavily corroded, it should be replaced. Oth-
erwise, the tire may separate from the wheel or cause loss of handling con-
trol.
■Wheel selection
When replacing wheels, care should be taken to ensure that they
are equivalent to those removed in load capacity, diameter, rim
width, and offset.
Replacement wheels are available at your Lexus dealer.
Lexus does not recommend using:
• Wheels of different sizes or types
• Used wheels
• Bent wheels that have been straightened
■ Aluminum wheel precautions
●Use only Lexus wheel nuts and wrenches designed for use with
your aluminum 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.

321
4-3. Do-it-yourself maintenance
4
Maintenance and care
08_IS350/250_U_(L/O_0708)
CAUTION
■When replacing wheels
●Do not use wheels that are a different size from those recommended in the
Owner’s Manual, as this may result in loss of handling control.
●Never use an inner tube in a leaking wheel which is designed for a tubeless tire.
Doing so may result in an accident, causing serious injury or death.
NOTICE
■Replacing tire inflation pressure warning valves and transmitters
●Because tire repair or replacement may affect the tire pressure warning valves
and transmitters, make sure to have tires serviced by your Lexus dealer or other
qualified service shop. In addition, make sure to purchase your tire pressure
warning valves and transmitters at your Lexus dealer.
●Ensure that only Genuine Lexus wheels are used on your vehicle.
Tire pressure warning valves and transmitters may not work properly with non-
genuine wheels.

5
When trouble arises
367
5-2. Steps to take in an emergency
08_IS350/250_U_(L/O_0708)
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 loading information
label). (If your vehicle has tires of a different size than the size indicated on the vehi-
cle placard or tire inflation pressure label [tire and loading information 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
monitoring system (TPMS-tire pressure warning system) that illuminates a low tire
pressure telltale (tire pressure warning light) when one or more of your tires is sig-
nificantly under-inflated. Accordingly, when the low tire pressure telltale (tire pres-
sure warning light) illuminates, you should stop and check your 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)
malfunction indicator to indicate when the system is not operating properly. The
TPMS (tire pressure warning system) malfunction indicator is combined with the
low tire pressure telltale (tire pressure warning light). When the system detects a
malfunction, the telltale will flash for approximately one minute and then remain
continuously illuminated. This sequence will continue upon subsequent vehicle
start-ups as long as the malfunction exists. When the malfunction indicator is illumi-
nated, the system may not be able to detect or signal low tire pressure as intended.
TPMS (tire pressure warning system) malfunctions may occur for a variety of rea-
sons, 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 tell-
tale 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.

415
6-1. Specifications
6
Vehicle specifications
08_IS350/250_U_(L/O_0708)
Steering
Tires and wheelsType A
Free playLess than 1.2 in. (30 mm)
Ti r e s i z e205/55R16 89W, T125/70D17 98M
(spare)
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)*
Spare:
60 psi (420 kPa, 4.2 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 5.8 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 indicated on the tire sidewall.
Wheel size16 × 7JJ, 17 × 4T (spare)
Wheel nut torque76 ft•lbf (103 N•m, 10.5 kgf•m)

416
6-1. Specifications
08_IS350/250_U_(L/O_0708)Ty p e B
Ti r e s i z e225/45R17 90W, 245/45R17 95W, T125/
70D17 98M (spare)
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)*
Spare:
60 psi (420 kPa, 4.2 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 4.5 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 indicated on the tire sidewall.
Wheel size17 × 8JJ, 17 × 4T (spare)
Wheel nut torque76 ft•lbf (103 N•m, 10.5 kgf•m)

417
6-1. Specifications
6
Vehicle specifications
08_IS350/250_U_(L/O_0708)Type C
Ti r e s i z e225/45R17 91V, 225/45R17 91V, T125/
70D17 98M
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)*
Spare:
60 psi (420 kPa, 4.2 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 size17 × 8JJ, 17 × 4T (spare)
Wheel nut torque76 ft•lbf (103 N•m, 10.5 kgf•m)

418
6-1. Specifications
08_IS350/250_U_(L/O_0708)Ty p e D
Ti r e s i z e
Front tires: 225/45R17 91V
Rear tires: 245/45R17 95V
Spare tire: T125/70R17 98M
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)*
Spare:
60 psi (420 kPa, 4.2 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 10 psi (70 kPa, 0.7 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 size17 × 8JJ, 17 × 4T (spare)
Wheel nut torque76 ft•lbf (103 N•m, 10.5 kgf•m)

419
6-1. Specifications
6
Vehicle specifications
08_IS350/250_U_(L/O_0708)Type E
Ti r e s i z e
Front tires: 225/40R18 88Y
Rear tires: 255/40R18 95Y
Spare tire: T145/70R17 106M
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)*
Spare:
60 psi (420 kPa, 4.2 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 size
Front wheels: 18 × 8J
Rear wheels: 18
× 8 1 /2J
Spare wheel: 17
× 4T
Wheel nut torque76 ft•lbf (103 N•m, 10.5 kgf•m)

424
6-1. Specifications
08_IS350/250_U_(L/O_0708)
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. 4 2 6 )
DOT and Tire Identification Number (TIN) (→ P. 4 2 6 )
Location of treadwear indicators (→ P. 306)
Tire ply composition and materials
Plies are layers of rubber-coated parallel cords. Cords are the strands
which form the plies in a tire.

426
6-1. Specifications
08_IS350/250_U_(L/O_0708)
Typical DOT and tire iden tification 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 size 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)