ILMA Compoundings February 2018 - 19

There is a definite shift in the low-temperature CCS and
Noack volatility characteristics when you are working with
different-quality base stocks in a finished engine formulation.
The best quality combination is associated with the highest
VI, but this is typically more expensive and not necessarily
what you need with a finished oil formulation. If your target
market is SAE 5W-30, the quality of base oil required is
different than if your market is SAE 0W-20. If your market
is SAE 0W-20 and GM dexos™1:2015 Gen 2 performance
coverage, the challenge is greater, as you now have to reach a
lower Noack target of 13.0 weight percent versus 15.0 weight
percent for API SN-Plus and ILSAC GF-5.
Do you target the synthetic market? The semi-synthetic
market? If so, how many storage tanks do you have? The
normal answer is very few, so you need to look for base
stocks that provide maximum flexibility and are readily
available and cost effective. Since base stock VI is a key element in the formulation puzzle, the first choice might be to
find the highest VI available for your product portfolio. You
can then formulate the highest quality of engine oil, and for
lower qualities you can blend with a less expensive Group II
base stock. Table 3 gives an example of how you can leverage
base stock VI with engine formulations.
The example shows the flexibility that base stock VI can
provide in formulating an engine oil. Since the blended base
oil target for a SAE 5W-30 engine oil is roughly 4.8 cSt at
100 degrees Celsius and a nominal 115 VI, using a high
Group III base stock is more quality than is required for
this product. So, you can offset or blend down the VI with
a conventional Group II base stock. The higher the VI, the
more Group II you can use to achieve the blended base oil
VI target. This is illustrated in Table 3.
Table 3:
Application of Base Stock VI to Formulation Sciences
Treat Rate, Normalized to 100%
Base Oil

Blend A

Blend B

Blend C

Group II

45.5

63.9

82.0

Group II+

54.5

Group III

36.1

Group III+

18.0

Total

100.0

Source: SGH Consulting LLC, ICIS Conference Presentation, Nov 2017. Note
that this is an illustration and not an actual blend study.

With the knowledge gained from understanding the value
of base stocks and their contribution to the finished oil formulation puzzle, how can one then leverage this knowledge

Figure 2:
Figure 2:
How to Leverage
in a Blending
Operation
How to Leverage
Group Group
III in a III
Blending
Operation

Group II+

100%
70%

Base Case
Group II+
Group II
MidViscosity

Advanced
Case Group III

Group III

Group II
MidViscosity

30%

SAE 5W-20 Conventional
4.8 cSt @ 100º CKV
114 V1
15 wt% NOACK
1820 cP @ -25º C CCS
SAE 5W-30 Conventional

100%
70%
50%
50%
30%

SAE 5W-20/30 Synthetic
SAE 0W-20/30 Synthetic
4.9 cSt @ 100º CKV
115 V1
15 wt% NOACK
1720 cP @ -25º C CCS

SAE 5W-20
Conventional
Part Synthetic

SAE 5W-20/30 Synthetic
SAE 0W-20/30 Synthetic

Red = new product options

into a day-to-day blending operation? An illustration of this
is shown in Figure 2, revealing the value of Group III, or
Group III+, to Group II+ in a blending operation.
Using Group II+ can easily achieve the viscometric properties required to formulate an SAE 5W-20 and SAE 5W-30
engine oil at the current API SN-Plus and ILSAC GF-5 performance level. Since Group II+ is not classified as synthetic,
the finished oils can be marketed only as conventional.
Therefore, for the Group II+ base stock, you essentially can
blend two conventional SAE 5W-20 and 5W-30 engine oils.
Now, if you simply substitute a Group III or a Group
III+ base stock in the tank used for Group II+, the available product choices increase significantly. You can still
blend the initial SAE 5W-20 and SAE 5W-30 conventional
engine oils; however, you can use more Group II in the
formulation to keep your finished oil costs under control.
Since Group III and Group III+ are classified as synthetic,
the blends with Group II can now be marketed as conventional or semi-synthetic. And if you use the Group III or
Group III+ by itself, you can formulate full synthetics and
pursue the lower SAE 0W-XX grades. This might require a
second, heavier Group III to maintain full synthetic status,
but the options available to the blender are now significantly expanded. With Group III, you can then pursue GM
dexos™1:2015 Gen 2 products.
In conclusion, knowing your base stock is critical to
achieving success with your blending operations. The market
has many choices, making the selection process more complex. But if you understand the pieces to the puzzle, you can
come up with some amazing possibilities.
Henderson is president of K&E Petroleum Consulting.

ILMA Compoundings February 2018

Table of Contents for the Digital Edition of ILMA Compoundings February 2018