Kinematic Viscosity, CCS Viscosity, Pour Point

Can someone explain what Kinematic Viscosity, CCS Viscosity mean?

Should you look for high or low numbers when comparing to other oils?

Which is most important when looking for the best cold flow properties? Pour point?

Reason for my question: The Amsoil Series 3000 5w-30 doesn't have as low of a pour point as Delvac 1 5w-40. Granted I'll most likely never see -60F, but I do see -20F. I want to know which one has the best cold flow and pumpability properties. Other than waiting for the cold day to do my baby food jar test, how can I tell?

Thanks for the help.

What is Viscosity?

-When a fluid is subjected to external forces, it resists flow due to internal molecular friction.
-Viscosity is a measure of that internal friction.
-Viscosity can be referred to as the measrement of a fluid's resistance to flow.

-Kinematic Viscosity,is a fluid's tendency to flow as visually indicated. Expressed in centistrokes cSt 1 square mm/1 second= 1cSt.

-Apparent Viscosity, A fuid's tnedency to flow as indicated by measured resistance. Expressed in centipoise cP.

-The load carrying ability of a fluid is directly related to the fluid's viscosity.

-The greater the viscosity of a fluid, the greater the loads it can withstand.
-The viscosity of a fluid mst be adequate to separate moving parts at the operating temperature of hte equipment.

-Differences in Viscosity,

-Too Low=metal to metal contact friction and wear, poor sealing and increased oil consumption

-Too high= Increased fluid friction, reduced energy efficiency, higher operating temperatures and equipment startig difficulties particularly at cold temperatures.

So to answer you question of do you want a high or low number, that is hard to do.
You want enough visosity to protect from metal to metal contact under high loads, but not too much visosity that you are reducing effeciency due to friction within the oil itself.

As per Tooslick:

<BLOCKQUOTE><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><HR>"You want to compare the CCS (Cold Crank Simulator) viscosities @ -25C
(-13F), between the Series 3000 and Delvac 1 ....The pour point is 5F above
the temperature when the oil solidifies, but the oil is too thick to pump
out of the crankcase at this temp, so it's a relatively meaningless number.
The practical low temp limit of a lubricant is defined by the borderline
pumping temperature or BPT ....The BPT is generally 15F-20F higher than the
pour point. The comparative CCS viscosities are shown below:

Series 3000: 2566 Cp @ -25C

Delvac 1: 3200 Cp @ -25C

So the Series 3000 is about 20% thinner at low temps, which is a good thing ..."
<HR></BLOCKQUOTE>

[ April 20, 2001: Message edited by: msparks ]

MSPARKS,

Thanks for the replies. That's the comparison I'm looking for. I'm looking forward to using that 15w-40 HD Marine Oil I bought from you. As I indicated before, I plan on changing my oil twice a year, once in the Fall to put in my cold weather oil and once in the Spring to put in my warm weather oil. My debate was whether or not to try the Series 5000 or go with Delvac for the Winter. I'd like to stick with one brand. If my Summer run of 15w-40 shows good numbers at analysis time, I'll probably go with Series 5000 for the Winter, especially now since you've cleared up the CCS Viscosity question. Its still strange that Delvac 1 can have a lower pour point, but have a higher CCS Viscosity. I would think that the Series 3000 would pump better, but you never know. Thanks again. I'll keep you posted.

Cummins Guy,

Go ahead and run your freezer test ...you'll see the Series 3000 flows better. One reason is that it requires less VI modifier to make a 5w-30 than a 5w-40. In the wintertime you really don't need (or want) a 40wt oil, as you will be running lower oil temps. Your oil pressure running the Series 3000 in cold weather should be comparable to running the Amsoil 15w-40 in hot weather. If it were my vehicle, I'd simply run the Series 3000 year round, with oil analysis and filter changes every 7500 miles.

TooSlick