I am running a full synthetic in all my diesels that run in the winter.
It is sold by a Canadian company,which brands it under their own label.
They are based in Alberta,and have branches in Yukon and Alaska.
AFD is their initials,which is Alberta Fuel Distributors or Arctic Fuel Distributors in Alaska.
I thought i would try it because others recommended it.Plus it is reasonably priced.So far i have no complaints the C7 cat in my rollback has used hardly any oil since i changed it,most is probably leaks by the black dots on the floor where it is parked in the winter.The Kenworth which lives outside and gets used every week does use some oil still but way less than the Rotella.
I have a moose gooser on the KW so it is a pain to add oil,so that is my Butt dyno so to speek.I added oil last week and was trying to remember the last time it was done,and it must of been last winter because the bungy cord that holds my winter front was still on the gooser and had to be removed to let it down.
My experiences with Rotella Synthetic... others may vary.
But if interested i believe there are a few oil threads on here for amusement and reading.
Thomas