I have an 05 X5 with the 3.0 and I love it, I havent had really any issues with it. The colling system in the 3.0 is exactially the same as in the e46. I have taken the X5 off road in several different conditions and it never once let me down. And the cost of maintenance isnt that much if you source your parts correctly. And you still get to use real oem. And the MPG in the 3.0 is decent as well with good power. I would recomend it.
Edit** Also the 4.4 doesnt really have that much more power over the 3.0 and for its fuel consumption, I don't think it would really be worth it. Just my 2 cents.
Last edited by Patton323I; 01-23-2013 at 05:35 AM.