oil technical data number, what do they mean?

[JetSnake]

What do the numbers mean or what do you look for in finding an oil that performs better when looking at the oil technical data sheet that is pinned on the top? I know what "pour" and "flash" mean but I'm haveing trouble with the C100 and the left side of the list.

[ July 05, 2006, 12:18 PM: Message edited by: JetSnake ]

 

[TomJones76]

JetSnake,

Can you link us to an example data sheet?
I'm thinking C100 might mean "viscosity in centistrokes at 100 degrees celsius".
Check out the SAE J300 chart for a range of these numbers versus oil weight ratings, also the explanation of viscosity on this link:
http://www.texacoxpresslube.com/carcare/article_viscosity.html

 

[JetSnake]

After reading my post I realize I didn't explain myself too well. On the top of the "car and truck gas engine oil" page there is a pinned topic "oil technical data 1-5-2005". In there is has a list of oil rating 100C, 40C, VI, HTHS, and CCS. I was wondering what they mean and the numbers below them and do you want a higher or lower number?

 

[AndyH]

100C = Viscosity @ 100°C, measured in cSt (centistokes)
40C = Viscosity @ 40°C, measured in cSt (centistokes)
VI = Viscosity Index
HTHS = High-Temp, High-Shear
CCS = Cold Cranking Simulator Viscosity, cP (°C )

Some of these terms can be found here:
http://theoildrop.server101.com/ubb/ultimatebb.php?ubb=get_topic;f=1;t=009552

And others here:
http://www.bobistheoilguy.com/oilglossary.html

I found this description of the Cold Cranking Simulator Viscosity:

quote:

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COLD CRANKING SIMULATOR APPARENT VISCOSITY (ASTM- D-2602):

Viscosities that are reported using the kinematic viscosity glass capillary test method do not adequately represent how a motor oils performs under cold cranking conditions. Therefore the Cold Cranking Simulator (CCS) test was developed in order to predict the cold cranking properties of oils used in automotive and truck crankcases. A 5 ml sample of oil is placed in the shear zone of the CCS test machine at room temperature. The shear zone consists of a rotor and stator. Coolant then begins to flow in order to drop the temperature of the oil. After three minutes the engine is run for one minute before the machines rotor speed is read. The CCS viscosity is determined in centipoises (cP) by referencing the speed readings obtained with a special calibration curve determined by standard reference oils. The resultant viscosity is called the apparent viscosity at low temperature. This test is extremely useful in predicting engine-cranking viscosities at specified low temperatures and how easily an engine will start in cold temperatures.

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And this description of HTHS:

quote:

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HIGH TEMPERATURE/HIGH SHEAR VISCOSITY (ASTM D-4683)

This is a severe service test that measures the viscosity under high temperatures and high shear rates and is measured in units of centipoise. Lubricants with high values in this test will maintain their viscosity in high engine operating temperatures and when exposed to high load/high shear conditions.

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And this description of Viscosity Index:

quote:

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VISCOSITY INDEX (ASTM D-2270)

The viscosity index is used to determine how much a particular motor oils viscosity changes with temperature. It is a method of applying a number to this rate of change based on a comparison with two arbitrary selected oils (published in tables by the ASTM at a given temperature typically 40 deg. C and 100 deg. C) that have significant variations in viscosity index. A high viscosity index would indicate a low rate of change of viscosity with temperature while a low viscosity index would indicate a high rate of change of viscosity with temperature. High viscosity index motor oils protect better in engines that operate with temperature variations, which includes all auto and light truck engines. Motor oils that have a large amount of viscosity index improvers tend to degrade more rapidly than motor oils that have less viscosity improvers. Synthetic oils, by their inherent nature, have significantly less viscosity improvers than an equivalent viscosity in a petroleum oil and thus tend to have high viscosity index values and are more stable.

---

And this description of Kinematic Viscosity:

quote:

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KINEMATIC VISCOSITY (ASTM D-445)

Kinematic viscosity is a measurement of the time taken for a known volume of oil to flow under gravity through a calibrated glass capillary viscometer. Kinematic viscosity is measured at 40 deg. C. (104 deg. F) and 100 deg. C. (212 deg. F.) in order to have standard reporting temperatures. It is essentially the ratio of the viscosity to the density of the oil being tested.

Kinematic viscosity is typically measured in centistokes (cSt). Centistokes can be thought of as the result of dividing the dynamic viscosity of an oil by its density, both measured at the same temperature. Dynamic viscosity (measured in centipoise or in Pascal seconds) is the force required to overcome fluid friction in an oil film of a known dimensions and thickness. I will not go into detailed engineering descriptions and calculations of dynamic viscosity as it gets into complex engineering calculations. I will explain kinematic viscosity in relation to practical applications in the selection of a multi viscosity 30-weight motor oil in section 23 of this book.

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The above quoted descriptions were found on what appears to me to be an Amsoil salesman's web site:
http://www.performanceoiltechnology.com/lubricanttesting.htm

 

[Ken2]

The data sheet doesn't tell much. Actual operation of the oil and used oil analysis tells the real story. The data sheet usually tells nothing about the quality of the base oils nor the quality of the additives used. The base oils are listed in Groups, but even then there is a difference in quality within the groups. Here's Chevron's base oil sheet which shows some of these quality differences that never show up on a data sheet.
https://chevron.com/products/prodserv/BaseOils/comp_med.shtml


Ken

 

[TomJones76]

Ken2 has a very good point.
You can VERRRY rarely determine much about "which oil is better" from a data sheet....
I get more mileage from comparing oils from the same blender to one another... sometimes interesting patterns show up.