2003 Lexus GS300 Engine

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 experience 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
75 L (19.8 gal., 16.5 lmp.gal.)

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 ignition
switch to ªACCº or ªLOCKº 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 OIL
CONSUMPTION
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.

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.
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 ºChecking the
engine oil levelº on page 260.

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
62G005d

GS430
GS300
With the engine at operating temperature and turned off,
check the oil level on the dipstick.
1. To get a true reading, the vehicle should be on a level spot.
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.

62g031

GS430 1Add oil 2O.K. 3Too full
62g032

GS300 1Add 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 line ( 5
) and the
low line ( 4
), it is O.K.
NOTICE
Be careful not to drop the engine oil on the vehicle
components.

62G007e

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 fill
between the low level mark and the full level mark on the
dipstick is indicated below for reference.
When the level reaches within the correct range, return the
filler cap and turn the cap clockwise until you hear a click.
Oil quantity. L (qt., lmp. qt.) 1.8 (1.9, 1.6)
NOTICE
Be careful not to spill the 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
ªToyota Genuine Motor Oilº is filled in your Lexus vehicle. Use
Lexus approved ªToyota Genuine Motor Oilº or equivalent to
satisfy the following grade and viscosity.
Oil grade: API grade SL ªEnergy±Conservingº or ILSAC
multigrade engine oil.
Recommended viscosity: 5W±30
62sa08
Temperature range anticipated before next oil change
SAE 5W±30 is the best choice for good fuel economy, and
good starting in cold weather.
If SAE is not available, SAE10W±30 may be used.
However, it should be replaced with 5W±30 at the next oil
change.
Oil identification marks
62L038

API Service Symbol
ILSAC Certification Mark
Either or both API registered marks are added to some oil
containers to help you select the oil you should use.
The API Service Symbol is located anywhere on the outside
of the container.
The top portion of the label shows the oil quality by API
(American Petroleum Institute) designation such as SL.
The center portion of the label shows the SAE viscosity
grade such as SAE 5W±30. ºEnergy±Conservingº, shown
in the lower portion, indicates that the oil has fuel±saving
capabilities.
The ILSAC (International Lubricant Standardization and
Approval Committee) Certification Mark is displayed on the
front of the container.

To ensure excellent performance for your engine, the ªToyota
Genuine Motor Oilº range is available, which has been
specifically tested and approved for all Lexus engines.
Please contact your Lexus dealer for further details of the
ªToyota Genuine Motor Oilº range.CHECKING THE ENGINE COOLANT
LEVEL
62G028

GS430 1Reservoir cap 2Upper line 3Lower line
62G004±1

GS300 1Reservoir cap 2Upper line 3Lower line