FWIW, When I bought my 04' the salesman told me because of the 6.0 a 'top tier fuel' should be used, nothing cheap! I've personally never tried it albeit I have a 800 mi road trip in a couple weeks, I'll give some premo fuel from Minneapolis a shot on my run home and see if it makes a difference. Top Tier stations are few and far between up here in the Dakotas, cheapo Tesoro and BP
