I think it’s unlikely Amsoil would be blending a Group III+ wax isomerate for the XL line. Didn’t some Amsoil rep say in some other thread they were using a hydroprocessed GIII? I don’t think a GIII+ would have much (if any) cost advantage over a PAO, so if Amsoil was looking to make a more cost effective GIII synthetic, a GIII+ would not really be the way to go. GIII+ are top line basestocks with VI’s higher than most PAO’s -- and limited production compared to hydroprocessed GIII.
For the NOACK of GIII based motor oils, the GIII+ base oils don’t really seem to have much (if any) of an advantage in NOACK over the hydroprocessed GIII’s (at least according to my reading of the published specifications). And PAO base oil volatility advantage over good GIII’s also seems marginal.
… … … … … … … … NOACKS …
Neste PAO 4.0 cSt …13.5
C-P …PAO 4.0 …… 13.0… … … (C-P = Chevron Phillips)
Neste GIII 4.3…… 14.4 … … … (hydroprocessed)
Neste PAO 5.8 …6.5
C-P …PAO 6.0 … 6.5
Neste GIII 6.0 … 5.7
Neste PAO 7.9 …3.2
C-P …PAO 8.0 … 3.0
Neste GIII 8.0 …3.5
It seems the advantage of blending with PAO’s over GIII (for NOACK) is that PAO’s flow better in the cold, so one can blend with higher viscosity base oils and still meet the CCS and MRV for that oil blend. For example, suppose a GII based 5w30 is blended with ~ 5.0 cSt base oils. A GIII based 5w30 could meet the same cold specifications using 5.5 cSt base oils, and a PAO could do it with 6.0 cSt base oils. A 0.5 cSt base oil difference could amount to several NOACK percentage points, so the PAO would get an advantage simply on that account. GIII+’s have better cold flow properties than GIII so they would have a similar advantage over the GIII’s like the PAO’s do.
If Amsoil was using a ~ 6.0 cSt GIII for their XL 10w30, then the NOACK could easily be in the 6.0 - 7.0 range (other GIII base oils like Yubase/ S-Oil are not quite as good as the 6.0 cSt Neste GIII which seems exceptional). When I blended a 6.0 cSt
S-Oil it came out to 6.7% NOACK (not as good as the Neste 6.0cSt), but an exact match for the 6.7% of the XL 10w30. (note -- I’m not suggesting Amsoil is using S-Oil or blending at 6.0 cSt, it’s just an example hopefully in the ballpark for what one might expect with a GIII).
As an aside -- Amsoil seems to have made an effort to put accurate numbers in their spec. sheets for motor oils, but a lot of manufacturers don’t seem to make much of an effort to provide very accurate product-data-sheets. You look at one motor oil spec. sheet, and it reads Flash Point …200 …200…200 … 200 … straight across for 5w-20 to 10w-40. That’s just plain goofy.
It’s like the engineer said to the secretary … “I don’t have the exact numbers handy… so just put 200 in there.”
For the average person a 10w30 is a 10w30 is a 10w30 -- they’re pretty well all the same, and it doesn’t matter, but for oil enthusiasts it’s a different story. We have people here…
… who run a 10.7 cSt 10w30 and think their engine felt a little sluggish -- so they are looking for a 10.5 cSt 10w30.
On that score, it’s hard to make much sense of the base oils sometimes when many of the PDS’s don’t seem all that accurate.
