Chevrolet 1986 Corvair Owner's Manual page 36

ENGINE OIL REQUIREMENTS
Engine Oil Recommendations
Use only "first line" oils which, according to the
label on the can, are (1) intended for service MS, and
(2)
pass car makers' tests
(including General Motors
Standard GM 6041-M. The
oil change interval, as rec-
ommended in this section on
oils, is based on the regular
use of oil of this quality of
engine oil. The majority of
the suitable oils currently
available are multi-viscosity
(e.g., 10W-30) products.
NOTE: Non-detergent and
other low quality oils are
specifically not recommended . The use of proper engine
oils and oil change intervals are your best assurance of
continued reliability and performance from your Corvair
engine.
The use of "break-in" oils, "tune-up" compounds,
"frictIon-reducing" compounds, etc., in your Corvair
engine are not recommended. However, there are
additive supplements available that can be helpful
under certain conditIons. For example, if higher deter-
gency is required to reduce varnish and sludge deposits,
a thoroughly tested and approved concentrate- "High
Detergency Concentrate"
*
-is available at your Corvair
'or " Engine Oil Supplement"'
33
dealer who can advise you regarding its use.
NOTE:
When checking
or
adding oil, be
care-
ful to
avoid spilling
or
dropping oil
onto
the
engine shrouding.
Recommended Oil Viscosity: The following chart will
serve as a guide in selecting the proper oil viscosity.
The proper viscosity helps assure good cold starting
by reducing friction and thus increasing cranking speed.
ANTICIPATED
RECOMMENDED SAE VISCOSITY OIL
TEMP.
SINGLE VISCOSITY MULTI-VISCOSITY
Above Freezing
(+32° F.)
SAE-20W SAE-10W-30
Below Freezing
and Above 0° F. SAE-10W SAE-10W-30
Below 0° F. SAE-5W
SAE-5W-20
NOTE: When changing oi/ consider the anticipoted temperatures for
the next 4 months.
SAE 5W and 5W·20 oils are not recommended for sustained high
speed driving.
SAE 30 and SAE· 20W-40 oils may be used at temperatures above
90°F.
SAE 5W-30 oils may be used at temperatures be/ow 32°F.
SAE IOW-40 oils may be used at temperatures between 0 and
90~F.
Checking Oil Level: The engine oil should be main-
tained at proper level. The best time to check it is
before operating the engine or as the last step in a
fuel stop. This will allow the oil accumulation in the
engine to drain back to the crankcase. To
ch~eck
the