A quick peak at the German forum where I hang out, reveals practically NOBODY with a 4.8i. Tons of 3.0d and 3.0sd models, a couple 3.0si, and no one silly enough to bother with Sir Drinks-a-lot-of-Petrol.

I have had a 3.0sd for 7 months, the performance for the type of vehecle is fantastic, i had an original e53 X5 3.0d (184bhp) and the performance was lacking, but the e70 with 286bhp is just perfect. I think you should take it the diesel will be as fast in the real world as the 4.8 V8, if not better and do 40 / 50 % more miles per gallon.