I originally only used Shell because back then their stations here in town still said it was a premium diesel, their signs have all since changed though. I stopped using Shell after a few months because for some reason every Shell station I tried the pumps would pump PAINFULLY slow on the BMW even though worked perfectly on the Mercedes and Ford. Since then I have exclusively used Chevron but I think one time when we used the BMW on a road trip and had to fillup at so no name place. I typically always use Chevron anyway even before we got the BMW, big reason being my wife works for Chevron and for years with additives, so we have a very good idea of the quality of what we are buying.
--Admiral Aaron Rouse