One other aspect you should research is cost-effectiveness. I paid $6k more than the 3.0 I had for two weeks for my almost fully loaded 4.4 (nav) which is only missing the activity pack. The 3.0 I had was almost fully loaded also but most of the stuff is standard on the 4.4 so I attribute the extra $6k for the substantial higher torque power of the v8 as well as the better bulldoggish look of the twin pipes, giant wheels and tires. I'm new to this board and I would like to find out a couple of answers. I have a mercedes SLK 230 that I am trading in for an X53.0. I have heard that the 3.0s are a lot better on gas, but obviously slower. Does anyone know of any sites for performance parts for the X5? Has anyone done anything to their X5s? I'd get the V8 but it is too expensive for me and plus the gas. Thanks for any input.