Group I Versus Group II

As you haven't recieved any hits on this yet, perhaps this paper I prepared on this subject can start the ball rolling. Write back with any questions.

"What do Group I, II, and III mean, and what’s so great about Group II and Group III?
Groups I, II, and III are broad categories of base stocks developed by the American Petroleum Institute for the purpose of creating guidelines for licensing engine oils. Typically, solvent-refined base oils fall into Group I, while hydroprocessed base stocks fall into Group II. Unconventional Base Oils (UCBOs) or Very-High VI stocks are normally categorized as Group III.
Group II+, though not an official API designation is a term used increasingly to describe Group II stocks of higher VI (110-119) and lower volatility than typical group II stocks.
Group I oils contain high levels of sulfur and aromatics, which are compounds that can diminish performance. Group II & III oils have lower levels of these impurities, which result in enhanced oxidation performance for fully-formulated lubricants. Thanks to Chevron’s proprietary ISODEWAXING technology, Chevron’s Group II and III base oils have a unique low-wax composition, which delivers better low-temperature performance compared to many other base oils.
Due to their high level of purity, Chevron Group II & III base oils provide additional benefits in crankcase applications. For example, in heavy-duty engines, motor oils made with Chevron base oils have demonstrated a soot dispersancy markedly higher than those made with competing base oils. They have also demonstrated potential for greater fuel economy in passenger car engine oils.
What’s so good about all-hydroprocessed base stocks?
Because all-hydroprocessed Group II & III stocks are manufactured with no solvent refining steps, when it comes to purity, they far surpass Group II or III base oils made in "hybrid" plants that maintain some solvent processing. In fact, they contain the lowest levels of impurities currently available in mineral-based oils, which, in turn, gives them a significant performance advantage

. What makes Chevron base oils more resistant to oxidation?
ChevronTexaco base oils contain lower levels of reactive compounds compared to solvent-refined Group I and, in some cases, other Group II base oils. These "impurities," which include aromatics and sulfur compounds, are much more susceptible to oxidative attack. Once these compounds begin to oxidize, a complex chain of reactions occurs that ultimately causes both the base oil and the additive to degrade. The virtual absence of these "bad actors" means Chevron base oils deliver exceptional resistance to oxidation."

Hope this helps a bit.

Thanx a lot hawk!

If it's show better performance when used in crankcase oil, that means the hydrofine base oil's also promising much-much better performance (compare to the solvent-refined mineral base oil) for compressors right?

And that also mean longer drain interval in my opinion.

thanx once again

Right on both counts Inuchio, but please maintain a good oil analysis program on your products. This allows you to protect your equipment and extend your drain intervals to their best potential.

Hi Hawk,

From a historical standpoint when did the transition from API Group I to II begin in North America? I am particularly interested in the industrial lubricants rather than PCMOs.

Could these dates be applied to other locales such as Europe or Australia or did this technology roll out there earlier or later?

Thanks.

Hi HAWK & INUCHIYO

It is great to know that you are reading about the recent developments on base oil technology.

Group I base are 60 - 70 % saturated and the remaining composition consists of impurities like aromtaics ,nitrogen,sulfur and colour bodies whereas Group II Plus hydrotreated base oils are 97 to 99% Saturated with hydrogen replacing the unsaturated portion in Group I.
In Real life terms Group II is like doubly refined cooking oil which reduces the risk to chloresterol in the blood.
Don't you consider the lubricant as the blood of the equipment?