Maybe they just want to use everything that comes out of the gtl process. Some of the base goes to QS and some to PUP.I did see a previous post from MolaKule where he talked about how the F/T process can be tweaked to produce different "weight" GTL base oils. I just wondered why with so much talk about Pennzoil Platinum 5W-30 being one of the thinnest 5W-30s, why not use a heavier base as they do for the Q/S Ultimate Protection 5W-30? Obviously, Shell can produce it. Is it about factory fills and gas mileage? Is it just cost based? Or, does the viscosity of a base oil not matter as much as we might believe?