I ran the e90 330d on premium, and either via placebo and not, its runs smoother and picks up quicker. When I had to put in Shell standard once, there was a distanct throttle lag at first (I would never ever put in supermarket)
This debate raged on and on within e90post. The main argument was if you have a high performance car (330d/335d) why on earth would you not put the best fuel in for the sake of a few quid?
Fifth Gear did a test and found out Premium Diesel does give more power!