2002 Lexus IS300 fuel consumption

SECTION 6 ± 2
303
SERVICE PROCEDURES AND
SPECIFICATIONS
Engine
Specifications304
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Fuel 306
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Fuel pump shut off system 308
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Facts about engine oil consumption 308
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Used engine oil 310
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Checking the engine oil level 310
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Checking the engine coolant level 313
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Spark plugs 314
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ENGINE
308
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 ºACCº or ºLOCKº 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 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.

ENGINE
309
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 310.