Originally Posted By: beast3300
Originally Posted By: HangerHarley
Originally Posted By: Quattro Pete
Originally Posted By: beast3300
I feel behind the times. When and why did the M1 change?
This is probably related to them starting to use Group III+ components, or VISOM as they call it.
Group III+?
What is?
I think it is gas to liquid. Something about using natural gas to make lubricating oil. Somebody will add more info.
Group IV (PAO) comes from natural gas also, IIRC. Read up on WWII history- Germany was so starved for crude oil after the allies finally got at Ploesti and other conventional refineries that virtually all of its lubricating oil and a lot of fuel was synthesized from natural gas.
From my reading, it appears that Group III+ includes varieties of of gas-to-liquid, severely hydroprocessed slack wax, or a mixture of both. At that extreme level of processing and chemical modification, it really doesn't matter anymore whether the starting product was crude oil or natural gas- the END product is extremely consistent and very much a man-made product, you can't throw the "not a real synthetic" accusation at it the way you can ordinary Group III stock. Shell's XHVI base (IIRC used in Rotella T6) is another example of a Group III+ base stock oil.