SAE Viscosity Grades for Engine Oils
Source: all about Motor Oil – web http://motorcycleinfo.calsci.com/Oils1.html
Source, Understanding the SAE Motor Oil Viscosity Standard – www.ideas4ag-ed.corn
Note: Straight Weights eg 10 20 30 40 50 60 are different than W grades eg 5W 10VV 20W
SAE Viscosity Grades for Engine Oils
the following tests are run in a viscosity measuring bath type apparatus – we have this – as per ASTM – D445 – vertical flow | cP = centipoise – mPa.s = milli Pascal-second – measured by Rheometer | |
Grade | Kinematic viscosity (cSt) Low Shear Rate at 1000C | Dynamic Viscosity (mPa.$) High Shear Rate at 150C |
20 | From 5.6 To 9.3 cST at 100c | 2.6 cP at 150c |
30 | From 9.3 To 12.5 cST at 100c | 2.9 cP at 150c |
40a | From 12 5 To 16.3 cST at 100c | 2.9 cP at 150c |
40b | From 12.5 To 16.3 cST at 100c | 3.7 cP at 150c |
50 | From 163 To 219 cST at 100c | 3.7 cP at 150c |
60 | From 21 9 To 261 cST at 100c | 37 cP at 150c |
A | Ow-40. 5w-40, 10w-40 grades | |
B | 15w-40, 20w-40, 25w-40, 40 grades | |
* | Winter Grades are designated by W after the number – eg 20W |
The following tests are run in a special test apparatus called – cold cranking simulator (CCS)
SAE J300 (1999) Motor Oil Grades – Low Temp. Specifications
Dynamic Viscosity (mPa.s) | |||
Grade | Cranking | Cranking Maximum | Pumping Maximum |
0W | 3,250cP at -30c | 6.200 at -35c | 60,000cP at -40c |
5W | 3,5000P at -25c | 6,600 at -30c | 60.000cP at -35c |
10W | 3,500cP at -20c | 700001 -25c | 60.000cP at -30c |
15W | 3,500cP at -15c | 7,000 at -200 | 60,000cP at -25c |
20W | 4.500cP at -10c | 9,500 at -15c | 60,000cP at -20c |
25W | 6,000cP at -Sc | 13,000 at -10c | 60 000P at -15c |
Oldest Specs. – SAE J300 (1911 ca.) Motor Oil Specifications
SAE Grade | Flow Rate at 100 C | Notes: |
10 | 0=14 Seconds | SAE started grading motor oil in 1911 |
20 | 15 To 24 Seconds | movement of different layers of fluid were |
30 | 25 to 34 Seconds | measured when subjected to a horizontal |
40 | 35 to 44 Seconds | force – 5 grades were identified |
50 | ‘=45 Seconds | SAE 60 was added later to the list |