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SAE Viscosity Grades

For engine and gear oils ccording to the SAE standards J 300 and J 306

Description

The viscosity grade of a lube oil is determined by the Society of Automotive Engineers (SAE). Oils can be separated into multigrade oils and monograde oils. Multigrade oils must fulfill two viscosity specifications, their viscosity grade consists of two numbers, e.g. 10W-40: 10W refers to the low-temperature viscosity ("Winter"), 40 refers to the high-temperature viscosity ("Summer"). Currently, most automotive engine oils are multigrade oils, while oils for restricted usage, e.g. for seasonally used engines like lawn mowers, are often monograde oils.

This page gives an overview of the oil specifications, see also the measurement data of engine oils and gear oils over a wide temperature range.

Measurement data

Automotive Lubricant Viscosity Grades: Engine Oils – SAE J 300, Dec. 1999

High-Temperature Viscosities

  • Kinematic viscosity at 40 °C and 100 °C - low-shear viscosity - determined according to ASTM D445, where the alternative method according to ASTM D7042 delivers comparable results.
  • High-shear viscosity (10/s) at high temperature of 150 °C - HSHT viscosity - determined according to ASTM D4683, CEC L-36-A-90 (ASTM D 4741) or ASTM DS481.
SAE
Viscosity
Grade[°C]
Min. Viscosity
[mm²/s]
at 100 °C
Max. Viscosity
[mm²/s]
at 100 °C
High Shear Rate Viscosity
[mPa.s]
at 150 °C
0W 3.8 -- --
5W 3.8 -- --
10W 4.1 -- --
15W 5.6 -- --
20W 5.6 -- --
25W 9.3 -- --
20 5.6 <9.3 2.6
30 9.3 <12.5 2.9
40 12.5 <16.3 2.9 *
40 12.5 <16.3 3.7 **
50 16.3 <21.9 3.7
60 21.9 <26.1 3.7

* 0W-40, 5W-40 & 10W-40 grades
**  15W-40, 20W-40, 25W-40 & 40 grades

Low-Temperature Viscosities

  • Cold-cranking viscosity at defined temperatures depending on the viscosity grade of the oil - determined according to ASTM D5293 (cold cranking simulator). The procedure simulates the cold start of an internal combustion engine.
  • Borderline pumping temperature of max. 60 000  mPa.s at defined temperatures depending on the viscosity grade of the oil according to SAE J300. Determination of apparent viscosity and yield stress according to ASTM D4684, ASTM D3829, ASTM D6821 or ASTM D6896 (mini rotary viscometer).
SAE
Viscosity
Grade[°C]
Cranking Viscosity
[mPa.s]
max. at Temp. [°C]
Pumping Viscosity
[mPa.s]
max. at Temp. [°C]
0W 6200 at -35 60 000 at -40
5W 6600 at -30 60 000 at -35
10W 7000 at -25 60 000 at -30
15W 7000 at -20 60 000 at -25
20W 9500 at -15 60 000 at -20
25W 13 000 at -10 60 000 at -15
20 -- --
30 -- --
40 -- --
40 -- --
50 -- --
60 -- --

Automotive Lubricant Viscosity Grades: Gear Oils – Excerpt SAE J 306, 1998

SAE
Viscosity
Grade
Max. Temperature
for 150 000 cP [°C]
(ASTM D 2983)
Min. Viscosity
[mm²/s] at 100 °C
(ASTM D445)
Max. Viscosity
[mm²/s] at 100 °C
(ASTM D445)
70W -55 3.72 --
75W -40 4.4 --
80W -26 5.29 --
85W -12 6.46 --
80 -- 8.02 <11.0
85 -- 10.15 <13.5
90 -- 13.13 <18.5
110 -- 17.4 <24.0
140 -- 23.74 <32.5
190 -- 33.33 <41.0
250 -- 48.49 --

Reference

SAE J 300, SAE J 306

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Metainformation

Reference   
SAE J 300, SAE J 306
Kin. vis. yes
Dyn. vis. no
Density no
Multiple temperatures no
Keywords kinematic viscosity, viscosity, engine oil, gear oil, lubricant, lube oil, SAE J 300, SAE J 306, viscosity grade

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