What base stock is Swepco 306 made from?

overdrivesteve

overdrivesteve

Member
Hi,
I'm trying to get an understanding of the oil lubrication recommendations for our trucks. This is a quote from your swepco pdf:
"it is manufactured from the very finest high vi paraffinic base stocks"

but what is a base vi stock and where does it fall in this quoted description of base stocks from this http://www.widman.biz/uploads/corvair_oil.pdf Source:

"
• group I - oils are solvent refined and normally low in natural viscosity index, although
some oil fields produce better grades than others. They have 20 to 30% aromatics, high
nitrogen and sulfur.

• group II - oils are hydroprocessed oils (or solvent refined and then hydrotreated).
Normally 92% to 99% of the molecules are saturated in the bombardment of hydrogen,
creating a clean, stable base oil and eliminating almost all aromatics, sulfur, and nitrogen.

• group II+ - oils are hydroprocessed to a quality somewhere between group II and group
iii.

• group iii - oils are severely hydroprocessed, creating base oils that under some conditions
give equal performance to traditional synthetic oils.

• group iv - oils are pao (polyalphaolefin) synthetics. These are excellent lubricants but
have very low solvency when used by themselves, not mixing well with other oils,
additives or contaminants, and causing hardening of seals and gaskets. Fully formulated
pao based oils use esters or other ingredients to increase their solvency.

• group v - oils are everything else synthetic. In general the esters and diesters of various
formulations are used to mix in small percentages with pao oils to give then the
necessary solvency and help them maintain a clean engine, softening the seals to avoid
leakage. The category also includes other types of oils used for specialty products or to
thicken group I, II, iii or iv oils.
"

and also can you please comment on this quote:

" shear strength of the base oil is more important than a few parts per million of zddp.
Synthetics will give the best protection, with group II oils next."

thanks.
Steve
 
Last edited:
Steve,

I was not available for a few days, and when I checked back there was a slug of posts regarding zddp, 502 & 306. I will try to address each one of the concerns in the order they were received, and you are first!

First of all, this will apply to all swepco products: swepco uses a proprietary formula in the products it manufactures, so I can only comment on certain restricted areas. Therefore, with that being said, I will not be able to disclose the group of the base stocks are used in any product.

However, with the 306 engine oil, I can tell you that it is a very high quality oklahoma crude that is used and it is solvent refined and hydrotreated. Oklahoma crude has more resistance to oxidation than it's next nearest brother, which is west texas crude. The way it was explained to me was that if a same amount of each were subjected to conditions which produce oxidation, the west texas crude would oxidize twice as fast.

As far as the shear strength quote is concerned, zddp is more commonly referred to as an antiwear/friction modifier. Synthetic oils must use some type of friction modifier as well, in fact red line oil uses a slug of it in their formulations. Some synthetics do not readily accept additives and must be blended with different base stocks to improve the solubility of the product. When the pao synthetics first became popular, a lot of oil blenders had problems with this, before they figured out that it had to be further blended. Although swepco 306 is not a semi-synthetic, or full synthetic, we have always tested well against them, even the racing oils.

I hope this answers your questions

dick
 
I'll stick with good ole " rotella t " for my IH motor's,since all I've used is that,even in my 10 year old motor I dumped a few $1000 in to rebuild it..since the rebuild,thats what I've used,an sure won't be using any synthetic oil's. Now for the older motor's with many miles on them,I don't think there's a chance to hurt them ? Jeff
 
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