I learned about it from the Camaro forums I'd read back when I had a 4th gen Camaro. Man, if I could have only gotten some that stuff I would have surely gained at least 50HP (in the Christmas Story narrator voice).
If you read the book, "In God We Trust. All Others Pay Cash" by Jean Shepherd, you'll be reading the stories (of his childhood) which were woven into "The Christmas Story". He is the narrator.
When Playboy Magazine got to interview The Beatles, they sent Jean Shepherd.
When "In God We Trust..." came out in paperback I was first in the book store. It was the only "first edition" I ever bought.
Also, I have an unbroken carton of Castrol 0W-30 marked "Made in Germany". Is that GC?
But GC had traditionally referred to the green tinted oil from the early 2000's. It was called GC because the German made stuff at the time was green, and to differentiate it from the previous made in USA 0w-30 that was normal amber color.
As far as that goes, the only way to tell is to check the date code. Caveat: I'm going off of memory from 15-20 years ago. I remember it had to be earlier than a 2005 date code, sometime in 2004 was the cut-off. There was no made in Germany before the green stuff, the 0w-30 was made in the USA until either the late 90's or early 00's. So if it's Made in Germany before late 2004, it's likely green. The date code was at the bottom of the bottle in white, and IIRC started with or contained XXyy (XX=year yy=week). So 0344 would be 44th week of 2003, which would be the green stuff. If anyone knows of a better way to tell, I'm all ears.
I couldn't take not knowing so I tore the 6 pack open......thus destroying any chance of a profitable "factory sealed case" sale on the rip-off marketplace.
Behold, I slid the receipt into the slot atop the box. Purchase date: 5/17/2010. The oil was an even $3/qt. (sigh). Evelyn was my checkerouter.
M072116ATWS161401 was on the first bottle...in white. Sooooooo, the 21st week of 2007.
M072116ATWS161402 was on the second bottle. I thought, "Wow, this IS German engineering!, they ordinate the bottles in a case!"
Alas, the "2 number" was on the remaining 5 bottles.
We start the bidding at $1,200. (insert cricket sounds here)
There is still a lot of it in Canada - Edge 0W-30 Made in Belgium. Sold in individual litre bottles; all Wal-Marts and Canadian Tires have it.
It doesn’t go on sale any more, and it is expensive - about $16-$17/litre. But you can still get it.