Originally Posted By: Quattro Pete
Also, are GTL stocks generally cleaner, thus resulting in less need for processing and cleaner/more uniform final product?
The process does produce more of the desirable molecules, but these are all complex mixtures of assorted hydrocarbons and deliver similar (but not identical) performance in motor oils. GTLs are more like Group III+, having more aliphatic (disirable) content and less aromaticity. Viscosity Index is the usual measure of aliphatic content, and the VI of the GTL base oils runs 135-145, the same basic range as Group III+.
Group III+ is not an official term, so Shell calls the GTL basestocks just Group III. I would expect these stocks will become commonly known as Group III+ once in the market.
Tom NJ