Industrial Lubricants

SAE Viscosity Grades for Engine Oils

SAE J300 Dec'99 The actual viscosity grade of a lubricant is determined by the Society of Automotive Engineers, for example SAE-15W40 for a multigrade oil and SAE-40 for a monograde oil. The first number (15W) refers to the viscosity grade at low temperatures (W from winter), whereas the second number (40) refers to the viscosity grade at high temperature.

SAE Low Temperature Viscosities High-Temperature Viscosities
Viscosity
Grade
Cranking2 (mPa.s)
max at temp °C
Pumping3 (mPa.s)
max at temp °C
Kinematic4 (mm2/s)
at 100°C
High Shear5 Rate (mPa.s)
at 150°C, 10/s
min max min
0W 6200 at -35 60 000 at -40 3.8
5W 6600 at -30 60 000 at -35 3.8
10W 7000 at -25 60 000 at -30 4.1
15W 7000 at -20 60 000 at -25 5.6
20W 9500 at -15 60 000 at -20 5.6
25W 13 000 at -10 60 000 at -15 9.3
20 5.6 <9.3 2.6
30 9.3 <12.5 2.9
40 12.5 <16.3 2.96
40 12.5 <16.3 3.77
50 16.3 <21.9 3.7
60 21.9 <26.1 3.7

1 - All values are critical specifications as defined by ASTM D3244
2 - ASTM D5293
3 - ASTM D4684. Note that the presence of any yield stress detectable by this method constitutes a failure regardless of viscosity. 4 - ASTM D445
5 - ASTM D4683, CEC L-36-A-90 (ASTM D 4741) or ASTM DS481
6 - 0W-40, 5W-40 & 10W-40 grades
7 - 15W-40, 20W-40, 25W-40 & 40 grades