Oh, and some of the threads with Doug's comments in them:
http://www.bobistheoilguy.com/forums/ubbthreads.php/topics/708004/1
http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=1096491
Originally Posted By: Doug Hillary
Hi,
jpr - Yes, and my viewpoint too. M1 0w-40 is a very sophisticated product with a substantial track record of OEM and end user satisfaction
It has been the Porsche factory fill since 2001
I was an original user of GC SLX 0w-30 in a wide range of engines. It was first released here in 12/1996 (it was Porsche Approved then) and it was in one of my Ford V6 engines by 01/1997 courtesy of Castrol.
I converted a number of other engines to it from the excellent Castrol "R" 10w-60. Sadly it failed to live up to my, VW's and MB's expectations here in OZ
Originally Posted By: Doug Hillary
Hi,
d00df00d - You said this:
"Early tests -- crude, but MUCH more informative than anything you will see on BITOG these days -- seemed to indicate that it was almost entirely PAO."
In its original API SH/CF form (1995-6) - as Formula SLX - it was a castor (ester) based and with a low phosphorous/low chlorine content
It was a flop and was withdrawn from sale here in its API SL/CF form around 2000. It left a trail of woes behind it
In many ways it was similar to one of Castrol's original synthetics - Formula R 15W-50 (API SE) of around 1978. It was caster based and red in colour. This product (now much modified) still exists as TWS 10W-60 (ester) or Edge 10W-60 (PAO). I assisted in the development of these great products over several years
Originally Posted By: Doug Hillary
Hi,
glxpassat - I was Field Testing a new semi-synthetic HDEO for Castrol at around the time Formula SLX was introduced here. It was a direct German import. I believe its demise was caused by a lack of extensive Field/Durability Testing. I think they simply got it wrong!!
In it's original ester content formulation it was prone to heavy varnish deposits in some engine families and this was the cause of my component faiure. It was dropped "like a hot spud" as a Service fill by major Euro OEMs
Later as it evolved into a PAO based product - along with API updates - it had lost Market share and user confidence had been irrepearably contaminated
In the late 1990s Castrol embarked on much more Field Testing aligned with OEMs like BMW, VW-Audi and third party engine development Companies in Europe - especially in Germany. They have continued in this vein
Not much remains now from the pre BP takeover days - what does are great products (Transmax Z, some gear oils and the 10W-60 ester/PAO range as examples)
And there's plenty more. He posted an entire history of it at one point, was quite interesting. He's a big fan of their gear lubes though, FWIW.