INFORMATION BEFORE DRI VING YOUR TOYOTA
393
FUNCTIONS OF ENGINE OI L
Engine oil has the primar y funct ions of
lubri cating and cooling t he insi de of t he
engine, and plays a major rol e in main-
taining the engine in proper work ing order.
ENGINE OIL CONSUMPTION
It is normal that an engine should con-
sume some engine oi l duri ng normal
engine operati on. The causes of oi l
consumption in a normal engine are as
follows.
D Oil is used to l ubric ate pis tons, piston
rings and cy linder s. A thin fil m of oil
is left on the c yli nder wall when a pis-
ton mov es downwards i n t he cy linder.
High negati ve pr essur e generat ed when
the vehicl e is decelerat ing suc ks some
of thi s oil into the combus tion chamber.
This oil as well as some part of the oi l
film left on t he cy linder wall is bur ned
by the high t emperature c ombusti on
gases duri ng the combus tion proc ess.
D Oil is als o us ed to lubr icate the s tems
of the intake val ves. Some of this oi l
is s ucked i nto the combustion c hamber
together wi th the intake ai r and i s
burned al ong wi th the f uel. H igh tem-
peratur e exhaus t gas es al so burn the
oil us ed t o lubric ate the exhaus t valv e
stems.
The amount of engine oil consumed de-
pends on t he viscosity of the oil, the
quality of the oil and t he condit ions the
vehicle is driven under.
More oil is consumed by high−speed driv-
ing and fr equent ac cel eration and decel-
erati on.
A new engine consumes more oil, sinc e
its pist ons, piston rings and cy linder walls
have not become condit ioned.
Oil consumption: Max. 1.0 L per 1000
km (1.1 qt./ 600 mil es, 0.9 Imp. qt./600
miles)
When judging t he amount of oil con-
sumption, note that the oil may become
diluted and make it difficult to judge
the true level accur ately.
As an exampl e, if a vehic le is us ed for
repeated s hort t rips , and c onsumes a nor-
mal amount of oil , t he dipst ick may not
show any drop in the oi l lev el at all, even
after 1000 k m (600 mi les) or mor e. Thi s
is bec ause the oil i s gradual ly becoming
diluted with fuel or moisture, making it
appear that the oil level has not c hanged.
The di luting i ngredients evaporat e out
when the vehi cle is then driven at high
speeds, as on an ex press way, mak ing it
appear that oil is exces siv ely c onsumed
after dr iving at high speeds .
IMPORTANCE OF ENGI NE OIL LEVEL
CHECK
One of t he most i mportant points in prop-
er vehic le maint enance is to keep the en-
gine oil at the optimum level so that oi l
funct ion will not be impair ed. Therefore, it
is es senti al that t he oil level be check ed
regular ly. Toyot a recommends that the oil
level be checked every time you refuel
the vehic le.
NOTICE
Failur e to check the oi l l evel regul arly
could lead to ser ious engine t rouble
due to insufficient oil.
For detail ed informati on on oil level c heck,
see “ Checki ng the engine oi l l evel” on
page 510 i n Section 7−2.
Finish
RAV4_EE
Facts about engine oil
consumption
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