Amsoil 0W30 Series 2000: Old vs New

[mpower]

How can one determine if the Series 2000 you've purchased is the "new" or "old" version that I hear discussed on BITOG?
Labelling? Batch no.?
I've been using 0W30 S2K for the last 2.5 years in my 1999 Grand Prix GTP (changed every 12,000 miles or about 1 year)
Some used oil analysis that I've seen with others on this board indicate thickening with the "old" version.

 

[Pablo]

I have no batch number I can give you. When did you purchase the latest batch?

In some cars it does thicken a bit when extended, has this been a problem for you?

 

[mpower]

The 0W30 S2K was purchased from the Missisauga, Ont. warehouse in July 2005.

 

[Pablo]

Probably not the newest formula, but why the worry? 12K is not a problem. Have you run a used oil analysis?

 

[mpower]

I'm not worried. No used oil analysis done. However, I previously ran Mobil 1 0W30 over the same duration/mileage and noticed two differences:
Lost 1/2 quart over 12000 miles with Mobil 1 vs. 1/4 quart with Series 0W30 series 2K.
Faster cranking speed at -25F with Series 2K vs. Mobil 1.
How can you tell the difference between old and new?

 

[Pablo]

Even 1/2 qt consumption over 12,000 miles is nothing. Interesting fact about the crank speed - the M1 should be a bit lower vis than the S2K.

Only initial viscosity. The newer formulation was introduced early fall or so.

 

[IslaVistaMan]

Get an oil analysis done by Blackstone. Here's a recent UOA I had done on my car that is definitely of the "old" S2K formulation:

http://theoildrop.server101.com/ubb/ultimatebb.php?ubb=get_topic;f=3;t=003126