 I am driving the all new 2009 X5 diesel since one month, approx. 1000 miles. Before I drove already the X5 3.0 I6 cylinder for 2 years and the X5 4.4 V8. The diesel engine fits that car best!! The torque is huge - no difference to the V8. The mileage is about 25 mpg, even in those days extreme winter temperatures. By the way I didn't had any winter problems so far.  The 2008/2009 update to the X5 is significant to the older models, e.g. more space in back row and trunk. Also remote trunk opener, keyless comfort entry, rear view camera are nice features. I love my all new X5 35d.