Engine Oils
Background & Properties
castrol.com/GPS
800 255 4417
May 2025
GPS
SAE Engine Oil Viscosity Grades
Comparative Viscosity Classifications
A16
cSt cSt
@1oo·c
@40·c
70
1,500
60
I
50 1,000
45
900
I
40
700
600
35
I
500
30
I
400
25
300
I
20
(.)
17.5
(.)
b
200
0
~
...
@
15
@
150
(/)
(/)
w
w
~
13
~
~
0
12
Iii
j::
100
j::
11
z
z
90
w
10
w
(.)
(.)
80
I
I
I
9.0
70
9.0
60
8.0
I
50
7.0
40
I
6.0
5.5
30
I
5.0
4.5
4.0
20
I
4.5
I
3.0
10
2.5
I
ISO
VISCOSITY
GRADE
1500
1000
680
460
320
220
150
100
68
46
32
22
15
10
I
EQUIVALENT
AGMA
LUBRICATION
NUMBER
I<=-@
I<=-@
I <=-0
I<=-@
I<=-@
l<=-0
I<=-@
I<=-@
l<=-0
I
I
I
I
SAE
GEAR
VISCOSITY
NUMBER
rr
250
140
90
~
~
~
SAE
CRANKCASE
VISCOSITY
NUMBER
50
40
30or
25W-30
20or
15W-20
o£]
~
VISCOSITIES AT VARIOUS TEMPERATURES ASSUME 95 VI OILS
NOTE: Viscosities at various temperatures are related horizontally.
SAE gear and crankcase specifications are at 100" Conly.
Muttigrade oil viscosities are not representaive at other temperatures.
SUS SUS
@100°F. @210°F.
10,000
9,000
8,000
7,000
300
6,000
250
5,000
4,000
200
150
3,000
150
2,000
u.: u:
b
1,500
b
0
...
...
(II
100
@ @
(/) (/)
90
C C
z
1,000
z
0
900
0
(.) (.) 80
w
800
w
(/)
700
(/)
.J .J
~
600
~
70
cc
500
cc
w w
=!: =!:
60
z z
:::)
400
:::)
!J !J
55
0 0
ca ca
~
300
~
(/) (/)
50
200
45
43
150
100
40
90
38
80
70
35
60
50 50
BRO,-COMPIAS
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