flat tire Lexus IS250C 2010 Service Manual

537
6-1. Specifications
6
Vehicle specifications
10_IS250C/350C_UType B
Ti r e s i z e
Front tires: 225/45R17 91V
Rear tires: 245/45R17 95V
Spare tire: 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 side-
wall.
Wheel size17 × 8J, 17 × 4T (spare)
Wheel nut torque76 ft•lbf (103 N•m, 10.5 kgf•m)

538
6-1. Specifications
10_IS250C/350C_UTy p e C
Ti r e s i z e
Front tires: 225/40R18 88Y
Rear tires: 255/40R18 95Y
Spare tire: T145/70D17 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 side-
wall.
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)

539
6-1. Specifications
6
Vehicle specifications
10_IS250C/350C_UType D
Ti r e s i z e
Front tires: 225/40R18 88W
Rear tires: 255/40R18 95W
Spare tire: T145/70D17 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 side-
wall.
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)

540
6-1. Specifications
10_IS250C/350C_UTy p e E
Ti r e s i z eFront tires: 225/40RF18 88V
Rear tires: 255/40RF18 95V
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 11.7 psi (80 kPa,
0.8 kgf/cm
2 or bar) to the front tires and rear
tires. Never exceed the maximum cold tire
inflation pressure indicated on the tire side-
wall.
Wheel sizeFront wheels: 18 × 8J
Rear wheels: 18 × 8 1 /2J
Wheel nut torque76 ft•lbf (103 N•m, 10.5 kgf•m)

546
6-1. Specifications
10_IS250C/350C_U
Radial tires or bias-ply tires
A radial tire has “RADIAL” on the sidewall. A tire not marked “RADIAL” is
a bias-ply tire.
TUBELESS or TUBE TYPE
A tubeless tire does not have a tube and air is directly filled in the tire. A
tube type tire has a tube inside the ti re and the tube maintains the air pres-
sure.
Load limit at maximum cold tire inflation pressure ( →P. 412)
Maximum cold tire inflation pressure (→ P. 5 3 6 )
This means the pressure to which a tire may be inflated.
Uniform tire quality grading
For details, see “Uniform tire quality grading” that follows.
Summer tire or all season tire (→ P. 412)
An all season tire has “M+S” on the sidewall. A tire not marked “M+S” is a
summer tire.
“TEMPORARY USE ONLY” (→ P. 4 9 1 )
A compact spare tire is identified by the phrase “TEMPORARY USE
ONLY” molded into its sidewall. This tire is designed for temporary
emergency use only.

550
6-1. Specifications
10_IS250C/350C_U■
Temperature A, B, C
The temperature grades are A (the highest), B, and C, representing
the tire's resistance to the generation of heat and its ability to dissipate
heat when tested under controlled conditions on a specified indoor
laboratory test wheel.
Sustained high temperature can cause the material of the tire to degenerate
and reduce tire life, and excessive temperature can lead to sudden tire fail-
ure.
The grade C corresponds to a level of performance which all passenger car
tires must meet under the Federal Motor Vehicle Safety Standard No. 139.
Grades B and A represent higher levels of performance on the laboratory
test wheel than the minimum required by law.
Warning: The temperature grades for this tire are established for a tire that
is properly inflated and not overloaded.
Excessive speed, underinflation, or excessive loading, either separately or in
combination, can cause heat buildup and possible tire failure.
Glossary of tire terminology
Tire related termMeaning
Accessory weight
The combined weight (in excess of those standard
items which may be replaced) of automatic transmis-
sion, 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)
Cold tire inflation pres-
sureTire 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 under that condition
Curb weight
The weight of a motor vehicle with standard equip-
ment, including the maximum capacity of fuel, oil and
coolant, and if so equipped, air conditioning and
additional weight optional engine

551
6-1. Specifications
6
Vehicle specifications
10_IS250C/350C_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

552
6-1. Specifications
10_IS250C/350C_U
Tire related termMeaning
Rim widthNominal distance between rim flanges
Vehicle maximum load on
the tireThe load on an individual tire that is determined by
distributing to each axle its share of the maximum
loaded vehicle weight, and dividing by two
Vehicle normal load on
the tire
The load on an individual tire that is determined by
distributing to each axle its share of curb weight,
accessory weight, and normal occupant weight (dis-
tributed in accordance with Table 1
* below), and
dividing it by two
We a t h e r s i d eThe surface area of the rim not covered by the
inflated tire

553
6-1. Specifications
6
Vehicle specifications
10_IS250C/350C_U
Tire related termMeaning
Bead
The 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 tire
A 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 com-
pounds
CrackingAny parting within the tread, sidewall, or innerliner of
the tire extending to cord material
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 tire
A 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

554
6-1. Specifications
10_IS250C/350C_U
Tire related termMeaning
Intended outboard side-
wall
(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 other side-
wall of the tire, or
(b) The outward facing sidewall of an asymmetrical tire that has a particular side that must always
face outward when mounted on a vehicle
Light truck (LT) tire
A tire designated by its manufacturer as primarily
intended for use on lightweight trucks or multipur-
pose 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
inflation 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
innerliner that extends to cord material
Outer diameterThe overall diameter of an inflated new tire
Overall width
The linear distance between the exteriors of the side-
walls of an inflated tire, including elevations due to
labeling, decorations, or protective bands or ribs
Passenger car tire
A tire intended for use on passenger cars, multipur-
pose passenger vehicles, and trucks, that have a
gross vehicle weight rating (GVWR) of 10000 lb. or
less.
PlyA layer of rubber-coated parallel cords