SECTION 6 ± 2
SERVICE PROCEDURES AND
SPECIFICATIONS
Engine
Specifications (GS430) 250. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Specifications (GS300) 253. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel256 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel pump shut off system258 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Facts about engine oil consumption258 . . . . . . . . . . . . . . . . . . . . . . . .
Used engine oil260 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking the engine oil level260 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking the engine coolant level264 . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking the radiator and condenser266 . . . . . . . . . . . . . . . . . . . . . . .
Spark plugs267 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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 three±way catalytic converter to lose its
effectiveness and the emission control system to
function improperly. Also, this can increase
maintenance costs.
Octane rating
Select premium unleaded gasoline with an Octane Rating
of 91 (Research Octane Number 96) or higher for optimum
engine performance. However, if such premium type
cannot be obtained, you may temporarily 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 additives to avoid build±up 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 specification for quality fuel named
World±Wide Fuel Charter (WWFC) that is expected to be
applied world wide. The WWFC consists of three
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.
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.
