Facts About Engine Oil Consumption - Toyota AURION Owner's Manual

INFORMATION BEFORE DRIVING YOUR TOYOTA
Facts about engine oil
consumption
FUNCTIONS OF ENGINE OIL
Engine oil has the primary functions of lubri-
cating and cooling the inside of the engine,
and plays a major role in maintaining the en-
gine in proper working order.
ENGINE OIL CONSUMPTION
It is normal that an engine should con-
sume some engine oil during normal en-
gine operation. The causes of oil con-
sumption in a normal engine are as
follows.
Oil is used to lubricate pistons, piston
D
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 cyl-
inder wall is burned by the high tempera-
ture combustion gases during the com-
bustion process.
Oil is also used to lubricate the stems of
D
the intake valves. Some of this oil is
sucked into the combustion chamber to-
gether with the intake air and is burned
along with the fuel. High temperature ex-
haust gases also burn the oil used to lubri-
cate the exhaust valve stems.
The amount of engine oil consumed de-
pends on the viscosity of the oil, the qual-
ity of the oil and the conditions the vehicle
is driven under.
More oil is consumed by high-speed driving
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., 0.9 lmp. qt.)
When judging the amount of oil consump-
tion, note that the oil may become diluted
and make it difficult to judge the true level
accurately.
190
As an example, if a vehicle is used for re-
peated 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
or more. This is because the oil is gradually
becoming diluted with fuel or moisture, mak-
ing 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. Toyota re-
commends 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
258 in Section 7-2.