Chevrolet Light - Page 73

"HEAVY~DUTY TYPE"-This term designates motor oil having
the oxidation stability. bearing corrosion preventive properties,
and deter gent disper:sant characteristics necessary to make it
generally suitable for use in both high speed Diesel and gasoline
engines under h eavy ~duty service conditions.
Regular , Premium and Heavy~Duty Type Oils. For the maxi~
mum protection of your Chevrolet Engine under all driving
conditions, it is recommended " that Hea vy ~Duty Type Motor
Oils be used. If the Heavy-Duty Type Oils are not available,
Premium Type Oils may be used. Under no conditions, except
for extremely light duty, should the Regular Type Oils be used.
S,A.E. Viscosity Numbers. The viscosity of a l ubricant is sim~
ply a measure of its body or fluidity.
The S.A.E. viscosity numbers constitute a classification of
lubricants in terms of viscosity or fluidity, but with no refer-
ence to any other characteristics or properties.
The S.A.E . viscosity numbers have been adopted by prac ~
tically all oil companies, and no difficulty shou ld be experi~
enced in obtaining the proper viscosity grade in the different
typ es of motor oils to me et seasonal requirements.
Viscosity Grades of Oil. The S.A.E. viscosity numbers consti-
tute a classification for crankcase lubricating oils in terms of
viscosity only. Viscosity numbers without an additional symbo l
are based on the viscosity at 210
0
F. Viscosity numbers with
the additional "w" are based on the viscosity at 0
0
F. The
viscosity of oils included in this classification for use in crank~
cases shall not be less than 39 SUS at 210° F. Other factors of
oil character or quality are not considered.
VNiu~m~be~~' ~~;;=V=~'=U'~;i~nt~~~~,,~s.~Ytbe~lt=u=ni~v.~S~"~·~t~~~
Mimmum Maximum Max.
10-W
O-W
20
30
40
50
6000 (Note A) Less than 12000 -
12000 (Note B) Less than 48000 -
45 Less than 58
58 Less than 70
70 Less than 85
85 Less than 110
Note A. Minimum VISCoSIty at O· F. can be waIVed prOVided vIscosity at
210 · F. is not below 40 Saybolt Seconds Universal.
Note B: Minimum Viscosity at O· F. can be waived provided viscosity at
210 · F. is not below 45 Saybolt Seconds Universal.
'71'