2006 Lexus GS430 engine

ENGINE
526
FUEL
Fuel type
Your vehicle must use only unleaded gasoline.
To help prevent gas station mixups, your Lexus has a smaller
fuel tank opening. The special nozzle on pumps with unleaded
fuel will fit it, but the larger standard nozzle on pumps with
leaded gas will not.
At a minimum, the gasoline you use should meet the
specifications of ASTM D4814 in the U.S.A. and CGSB
3.5−M93 in Canada.
NOTICE
Do not use leaded gasoline. Use of leaded gasoline will
cause the threeway catalytic converter to lose its
effectiveness and the emission control system to
function improperly. Also, this can increase
maintenance costs.
Octane rating
Premium unleaded gasoline with an Octane Rating of 91
(Research Octane Number 96) or higher required for
optimum engine performance. However, if such premium
type cannot be obtained, you may use unleaded gasoline
with an Octane Rating as low as 87 (Research Octane
Number 91). Use of unleaded fuel with an octane number or rating lower
than stated above will cause persistent heavy knocking. If
severe, this will lead to engine damage.
If your engine knocks ...
If you detect heavy knocking even when using the
recommended fuel, or if you hear steady knocking while
holding a steady speed on level roads, consult your Lexus
dealer.
However, occasionally, you may notice light knocking for a
short
time while accelerating or driving up hills. This is normal
and there is no need for concern.
Gasoline containing detergent additives
Lexus recommends the use of gasoline that contains
detergent a dditives to avoid buildup of engine deposits.
However, all gasoline sold in the U.S. contains detergent
additives to keep clean and/or clean intake systems.
Quality gasoline
Automotive manufacturers in the U.S., Europe and Japan
have developed a specificat ion for quality fuel named
WorldWide Fuel Charter (WWFC) that is expected to be
applied world wide. The WWFC consists of four
categories that depend on required emission levels. In the
U.S., category 3 has been adopted. The WWFC improves
air quality by providing for better emissions in vehicle
fleets, and customer satisfaction through better vehicle
performance.

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527
Cleaner burning gasoline
Cleaner burning gasoline, including reformulated
gasoline that contains oxygenates such as ethanol or
MTBE 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 performance, reduce
vehicle emissions, and improve air quality.
Oxygenates in gasoline
Lexus allows the use of oxygenate blended gasoline
where the oxygenate content 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.
Gasoline containing MMT
Some gasoline contain an octane enhancing additive
called MMT (Methylcyclopentadienyl Manganese
Tricarbonyl).
Lexus does not recommend the use of gasoline that contains
MMT. If fuel containing MMT is used, your emission control
system may be adversely affected. The Malfunction Indicator
Lamp on the instrument cluster may come on. If this happens,
contact your Lexus dealer for service.
Gasoline quality
In a very few cases, you may exper ience driveability problems
caused by the particular gasoline that you are using. If you
continue to have unacceptable driveability, try changing
gasoline brands. If this does not rectify your problem, then
consult your Lexus dealer.
NOTICE
 Do not use gasohol other than stated above. It will
cause fuel system damage or vehicle performance
problems.
 If drivability problems are encountered (poor hot
starting, vaporizing, engine knock, etc.), discontinue
its use.
 Take care not to spill gasohol during refueling.
Gasohol may cause paint damage.
Fuel tank capacity
71 L (18.7 gal., 15.6 lmp.gal.)

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528
FUEL PUMP SHUT OFF SYSTEM
The fuel pump shut off system stops supplying fuel to the
engine to minimize the risk of fuel leakage when the engine
stalls or an airbag inflates upon collision. To restart the engine
after the fuel pump shut off system activates, turn the engine
switch off once and start it.
CAUTION
Inspect the ground under the vehicle before restarting
the engine. If you find that liquid has leaked onto the
ground, it is the fuel system that has been damaged and
it is in need of repair. In this case, do not restart the
engine.
FACTS ABOUT ENGINE OILCONSUMPTION
Functions of engine oil
Engine oil has the primary function of lubricating and cooling
the inside of the engine, and plays a major role in maintaining
the engine in proper working order.
Engine oil consumption
It is normal that an engine should consume some engine
oil during normal engine operation. The causes of oil
consumption in a normal engine are as follows.
Oil is used to lubricate pistons, piston rings and cylinders.
A thin film of oil is left on the cylinder wall when a piston
moves downwards in the cylinder. High negative pressure
generated when the vehicle is decelerating sucks some of
this oil into the combustion chamber. This oil as well as
some part of the oil film left on the cylinder wall is burned by
the high temperature combustion gases during the
combustion process.
 Oil is also used to lubricate the stems of the intake valves.
Some of this oil is sucked into the combustion chamber
together with the intake air and is burned along with the fuel.
High temperature exhaust gases also burn the oil used to
lubricate the exhaust valve stems.

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The amount of engine oil consumed depends on the
viscosity of the oil, the quality of the oil and the way the
vehicle is driven.
More oil is consumed under driving conditions such as high
speeds and frequent acceleration and deceleration.
A new engine consumes more oil, since its pistons, piston rings
and cylinder walls have not become conditioned.
Oil consumption: Max. 1.0 L per 1000 km (1.1 qt./600 miles,
0.9 lmp·qt./600 miles).
When judging the amount of oil consumption, keep in
mind that the oil may have become diluted, making it
difficult to judge the true level accurately.
For example, if a vehicle is used for repeated short trips and
consumes a normal amount of oil, the dipstick may not show
any drop in the oil level at all, even after 1000 km (600 miles)
or more. This is because
the oil is gradually becoming diluted
with fuel or moisture, making it appear that the oil level has not
changed.
The diluting ingredients evaporate out when the vehicle is then
driven at high speeds, as on an expressway, making it appear
that oil is excessively consumed after driving at high speeds.
Importance of engine oil level check
One of the most important points in proper vehicle
maintenance is to keep the engine oil at the optimum level so
that oil function will not be impaired. Therefore, it is essential
that the oil level be checked regularly. Lexus recommends that
the oil level be checked every time you refuel the vehicle.
NOTICE
Failure to check the oil level regularly could lead to
serious engine trouble due to insufficient oil.
For detailed information on oil level check, see ”Checking the
engine oil level” on page 530.

ENGINE
530
USED ENGINE OIL
CAUTION
Used engine oil contains potentially harmful
contaminants which may cause skin disorders such
as inflammation or skin cancer, so care should be
taken to avoid prolonged and repeated contact with
it. To remove used engine oil from your skin, wash
thoroughly with soap and water.
 Do not leave used oil within the reach of children.
 Dispose of used oil and used oil filters only in a safe
and acceptable manner. Do not dispose of used oil
and used oil filters in household trash, in sewers or
onto the ground. Call your Lexus dealer or a service
station for information concerning recycling or
disposal.
CHECKING THE ENGINE OIL LEVEL
G62025
 GS430
G62002
GS300
With the engine at operating temperature and turned off,
check the oil level on the dipstick.

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531
1. To get a correct reading, the vehicle should be on level
ground. After turning off the engine, wait a few minutes for the
oil to drain back into the bottom of the engine.
2. Pull the dipstick out, hold a rag under the end and wipe it
clean.
3. Reinsert
the dipstick and push it in as far as it will go, or the
reading will not be correct.
G62006
 GS430
1
Add oil 2O.K. 3Too full
G62005
GS300 (twowheel drive models)
1
Add oil 2O.K. 3Too full

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G62006
GS300 (fourwheel drive models)
1
Add oil 2O.K. 3Too full
4. Pull the dipstick out and look at the oil level while holding a
rag under the end. If it is between the full level mark (
5 ) and
the low level mark ( 4 ), it is O.K.
NOTICE
Be careful not to drop engine oil on the vehicle
components.
G62023
GS430 GS300
If the oil level is below or only slightly above the low level
mark, add engine oil of the same type as already in the
engine.
Remove the oil filler cap and add engine oil a little at a time,
checking the dipstick. We recommend that you use a funnel
when adding oil. The approximate quantity of oil needed to
raise the level between low and full on the dipstick is indicated
as follows:
1.5 L (1.6 qt., 1.3 lmp. qt.)
For the engine oil capacity, see “Specifications” on pages 520
and 523.
When the level reaches within the correct range, return the
filler cap and turn the cap clockwise until you hear a click.

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NOTICE
Be careful not to spill engine oil on the vehicle
components.
 Avoid overfilling, or the engine could be damaged.
 Check the oil level on the dipstick once again after
adding the oil.
Engine oil selection
“Toyota Genuine Motor Oil” is used in your Lexus vehicle. Use
Lexus approved “Toyota Genuine Motor Oil” or equivalent to
satisfy the following grade and viscosity.
Oil grade: ILSAC multigrade engine oil.
Recommended viscosity: 5W −30
62L042
Outside temperature
SAE 5W30 is the best choice for good fuel economy, and
good starting in cold weather.
If SAE 5W30 is not available, SAE10W30 may be used.
However, it should be replaced with 5W30 at the next oil
change.