The lower SAE Viscosity Numbers, such
as
SAE 5W SAE
lOW
which represent the light body oils, are recommended for
use during cold weather to provide easy starting and instant lubri-
cation. The higher SAE Viscosity Numbers such as SAE 30 and
SAE 30W, which represent heavier body oils, are recommended
for use during warm
or
hot weather to provide improved oil econ-
omy and adequate lubrication under high operating temperatures.
Oils are available which are designed to combine the easy start-
ing characteristics of the lower SAE.Viscosity Number with the
warm weather operating characteristics of the higher SAE Vis-
cosity Number. These are termed "multi-viscosity oils," SAE
5W-20,
SAE
5W-30, SAE 10W-30, SAE 10W-40, SAE 20W-40.
The following chart will serve
as
a guide in selecting the proper
oil viscosity.
In
addition to providing proper lubrication, the cor-
rect viscosity helps assure good cold and hot starting by reducing
friction and thus·increasing cranking speed.
Please
Note:
•
SAE
5W-20
oils
are
not
recommended
for
sustained
high
speed
driving
.
•
SAE
30
oils
may
be
used
at
temperatures
above
40
degrees
F.
RECOMMENDED
SAE
VISCOSITY
NUMBER
I I I
•
'_l'_lIlY.t11ri(
••
tWIll.- •
I • I I I -.
I I I
•
1-
r I I I I I
-30
-20
0
20
40
60
80
100
TEMPERATURE
RANGE
ANTICIPATE!)
BEFORE
NEXT
OIL
CHANGE,
OF.
Types
of
Oils-
How
to
Determine
the
Quality
of
Oil
You
Are
Getting
In
service, engine oils may form sludge and varnish and, under
some conditions, corrosive acids unless protected against oxidation.
To
minimize the formation of these harmful products and to
assure the use of oil best suited for present day operating conditions,
automobile manufacturers have developed a series ofsequence.tests
designed to evaluate the ability of any oil to properly lubricate
automobile engines.
Only those oils which are certified by their suppliers
as
meeting
(a)
MS service requirements and
(b)
car makers tests are of the
quality
tQ
be used in Chevrolet engines.
7
