2008 Lexus GS450h Using the audio system / LEXUS 2008 GS450H OWNER'S MANUAL (OM30A96U)

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Fuel information
■Fuel tank opening for unleaded gasoline
To help prevent incorrect fueling, your Lexus has a fuel tank opening that only
accommodates the special nozzle on unleaded fuel pumps.
■If premium gasoline is not available
If 91 Octane cannot be obtained, you may use unleaded gasoline with an Octane
Rating as low as 87 (Research Octane Number 91). 
However, use of unleaded fuel with an Octane Rating lower than 91 may result in
engine knocking or drastically reduce output to protect itself while driving with a
heavy load. Persistent knocking can lead to engine damage and should be cor-
rected by refueling with higher octane unleaded gasoline.
■If your engine knocks
●Consult your Lexus dealer.
●You may occasionally notice light knocking for a short time while accelerating
or driving uphill. This is normal and there is no need for concern.
■Gasoline quality
In very few cases, driveability problems may be caused by the brand of gasoline you
are using. If driveability problems persist, try changing the brand of gasoline. If this
does not correct the problem, consult your Lexus dealer.
Your vehicle must use on ly unleaded gasoline.
Premium unleaded gasoline with an Octane Rating 91 (Research Octane
Number 96) or higher required for optimum engine performance.
At minimum, the gasoline you use should meet the specifications of
ASTM D4814 in the U.S.A. an d CGSB3.5-M93 in Canada.

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■Gasoline quality standards
●Automotive manufacturers in the US, Europe and Japan have developed a
specification for fuel quality called World-Wide Fuel Charter (WWFC) that is
expected to be applied worldwide.
●The WWFC consists of four categories that are based on required emission
levels. In the US, category 4 has been adopted.
●The WWFC improves air quality by lowering emissions in vehicle fleets, and
customer satisfaction th rough better performance.
■Lexus recommends the use of gasoline containing detergent additives
●Lexus recommends the use of gasoline that contains detergent additives to
avoid build-up of engine deposits.
●All gasoline sold in the US contains de tergent additives to clean and/or keep
clean intake systems.
■Lexus recommends the use of cleaner burning gasoline
Cleaner burning gasoline, including reform ulated gasoline that contains oxygen-
ates such as ethanol or MTBE (Methyl Tert iary Butyl Ether) is available in many
areas.
Lexus recommends the use of cleaner burning gasoline and appropriately blended
reformulated gasoline. These types of gasoline provide excellent vehicle perfor-
mance, reduce vehicle emissions and improve air quality.
■Lexus does not recommend blended gasoline
●Lexus allows the use of oxygenate blended gasoline where the oxygenate con-
tent is up to 10% ethanol or 15% MTBE.
●If you use gasohol in your Lexus, be sure that it has an octane rating no lower
than 87.
●Lexus DOES NOT recommend the use of gasoline containing methanol.

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■Lexus does not recommend gasoline containing MMT
Some gasoline contains octane enhancin g additive called MMT (Methylcy clopen-
tadienyl Manganese Tricarbonyl).
Lexus DOES NOT recommend the use of gasoline that contains MMT. If fuel con-
taining MMT is used, your emission control system may be adversely affected.
The malfunction indicator lamp on the inst rument cluster may come on. If this hap-
pens, contact your Lexus dealer for service.
NOTICE
■Notice on gasoline quality
●Do not use leaded gasoline. 
Leaded gasoline can cause damage to your vehicle’s three-way catalytic convert-
ers causing the emission control system to malfunction.
●Do not use gasohol other than that stated here. 
Other gasohol may cause fuel system damage or vehicle performance problems.
●Using unleaded gasoline with an octane number or rating lower than that stated
here will cause persistent heavy knocking. 
At worst, this will lead to engine damage.
■Fuel-related poor driveability
If after using a different type of fuel, poor driveability is encountered (poor hot start-
ing, vaporization, engine knoc king, etc.), discontinue the use of that type of fuel.
■When refueling with gasohole
Take care not to spill gasohol. It can damage your vehicle’s paint.

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Tire information
Ty p i c a l t i r e s y m b o l s
Tire size(P. 559)
DOT and Tire Identification Number (TIN) ( P. 5 5 8 )
Location of treadwear indicators ( P. 435)
Run-flat tire (RFT) or standard tire ( P. 5 2 7 )
This vehicle can be equipped with eith er run-flat tires (RFT) or standard
tires. A “RFT” or “DSST” mark is molded on the sidewall of the run-flat tire.

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Tire ply composition and materials
Plies are layers of rubber-coated parallel cords. Cords are the strands
which form the plies in a tire.
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 tire and the tube maintains the air pres-
sure.
Load limit at maximum cold tire inflation pressure ( P. 5 6 2 )
Maximum cold tire inflation pressure ( P. 5 6 2 )
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. 440)
An all season tire has “M+S” on the si dewall. A tire not marked “M+S” is a
summer tire.
“TEMPORARY USE ONLY”
A compact spare tire is identified by the phrase “TEMPORARY USE
ONLY” molded into its sidewall. This tire is designed for temporary emer-
gency use only.

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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 that the tire conforms to applicable
Federal Motor Vehicle Safety
Standards.

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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)
■ Tire dimensions
Section width
Ti r e h e i g h t
Wheel diameter

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Tire section namesBead
Sidewall
Shoulder
Tread
Belt
Inner liner
Reinforcing rubber
Carcass
Rim lines
Bead wires
Chafer
Uniform Tire Quality GradingThis information has b een prepared in accorda nce with regulations
issued by the National Highway Tr affic Safety Administration of the
U.S.A. Department of Transportation.
It provides the purchasers and/or pr ospective purchasers of Lexus vehi-
cles with information on uniform tire quality grading.
Your Lexus dealer will help answer an y questions you may have as you read
this information.