Page 513 of 573
5129-1. Specifications
IS350/250_U (OM53758U)
NOTICE
■Notice on fuel quality
●Do not use improper fuels. If improper fuels are used, the engine will be damaged.
●Do not use leaded gasoline.
Leaded gasoline can cause damage to your vehicle’s three-way catalytic converters
causing the emission control system to malfunction.
●Do not use gasohol other than the type previously stated.
Other gasohol may cause fuel system da mage or vehicle performance problems.
●Using unleaded gasoline with an octane number or rating lower than the level previ-
ously stated will cause persistent heavy knocking.
At worst, this will lead to engine damage.
■Fuel-related poor driveability
If poor driveability is encounte red after using a different type of fuel (poor hot starting,
vaporization, engine knocking, etc.), disc ontinue the use of that type of fuel.
■When refueling with gasohol
Take care not to spill gasohol. It can damage your vehicle’s paint.
Page 514 of 573
5139-1. Specifications
9
Vehicle specifications
IS350/250_U (OM53758U)
Full-size tire
Compact spare tire
Tire information
Ty p i c a l t i r e s y m b o l s
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 516 of 573
5159-1. Specifications
9
Vehicle specifications
IS350/250_U (OM53758U)
DOT symbol*
Tire Identification Number (TIN)
Tire manufacturer’s identification
mark
Ti r e s i z e c o d e
Manufacturer’s optional tire type
code (3 or 4 letters)
Manufacturing week
Manufacturing year
*: The DOT symbol certifies that the tire conforms to applicable Federal Motor Vehicle
Safety Standards.
Typical DOT and Tire Identification Number (TIN)
1
2
3
4
5
6
7
Page 517 of 573
5169-1. Specifications
IS350/250_U (OM53758U)
■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
Page 518 of 573
5179-1. Specifications
9
Vehicle specifications
IS350/250_U (OM53758U)
Bead
Sidewall
Shoulder
Tr e a d
Belt
Inner liner
Reinforcing rubber
Carcass
Rim lines
Bead wires
Chafer
Tire section names
1
2
3
4
5
6
7
8
9
10
11
Page 519 of 573

5189-1. Specifications
IS350/250_U (OM53758U)
This information has been prepared in acco rdance with regulations issued by the
National Highway Traffic Safety Administration of the U.S. Department of Trans-
portation.
It provides the purchasers and/or prospective purchasers of Lexus vehicles with
information on uniform tire quality grading.
Your Lexus dealer will help answer any questions you may have as you read this infor-
mation.
■DOT quality grades
All passenger vehicle tires must conform to Federal Safety Requirements in
addition to these grades. Quality grad es can be found where applicable on
the tire sidewall between tread shoulder and maximum section width.
For example: Treadwear 200 Traction AA Temperature A
■Tr e a d w e a r
The treadwear grade is a comparative rati ng based on the wear rate of the tire
when tested under controlled conditions on a specified government test
course.
For example, a tire graded 150 would wear one and a half (1 - 1 /2) times as well on
the government course as a tire graded 100.
The relative performance of tires depends upon the actual conditions of their use.
Performance may differ significantly from the norm due to variations in driving
habits, service practices and differences in road characteristics and climate.
■Tr a c t i o n A A , A , B , C
The traction grades, from highest to lowest, are AA, A, B and C, and they rep-
resent the tire’s ability to stop on we t pavement as measured under controlled
conditions on specified government te st surfaces of asphalt and concrete.
A tire marked C may have poor traction performance.
Warning: The traction grade assigned to this tire is based on braking (straight
ahead) traction tests and does not include cornering (turning) traction.
Uniform Tire Quality Grading
Page 520 of 573

5199-1. Specifications
9
Vehicle specifications
IS350/250_U (OM53758U)
■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 failure.
Grade C corresponds to a level of perfor mance which all passenger car tires must
meet under the Federal Motor Vehicle Safety Standard No. 109.
Grades B and A represent higher levels of performance on the laboratory test
wheel than the minimum required by law.
Warning: The temperature grades of a tire assume that it is properly inflated and
not overloaded.
Excessive speed, underinflation, or excessiv e loading, either separately or in com-
bination, can cause heat buildup and possible tire failure.