bmwwestcoast,

Your issue with the "lurching forward" as you come to a light is unfortunately normal. From what I can tell everybody with the E70 4.8i has this issue. Some have said getting a software update helps, others not. I think a lot of people don't even notice it because your typical bmw driver drives aggressively and in those cases the "lurch" is mostly undetectable.

I think the issue is that the transmission is very rough switching between 1st and 2nd gear and vice versa. Next time you are in the car at a stop try switching into manual mode and toggle between M1 and M2. I am pretty sure this is going to be the same _general_ feeling you are describing when coming to a stop. All cars lurch a little when moving between gears, but it seems much more pronounced on the 4.8i E70 than any other car I have driven.

What I think happens is that when you are coming to a slow stop (say you use the brake to come mostly to a stop and then coast the rest of the way at slow speeds) the transmission downshifts at the last second while you are coasting those last few feet or applying the brake softly to come to a full stop. Since you are braking slowly, you feel this hard shift. I can't tell whether this is the trasmission coming from a higher gear down to 1st or the transmission shifting at the end from 1st back to 2nd (since the X5 starts in 2nd from what I can tell).

I do not notice the "lurching" when I am driving agressively and braking hard into a stop or when slowing down from highway speeds to a stop, but I notice it all the time when driving in the city at moderate speeds (15-30 mph or so). This "lurching" issue drives me nuts too, but I noticed it much more for the first ~1200 miles when I was trying to carefully break her in. Try braking harder (i.e. wait longer to start applying the brakes and then brake stronger and continuously). This should make it less noticeable.

I should emphasive that I don't believe this is acceptable operating behavior on a $75k vehicle. If I am trying to drive cautiously (say with my wife and child in the car) then the transmission shouldn't feel like a teenager trying to drive stick for the first time...which it does when coming to slow stops at moderate speeds. From what I have heard the transmission on the 7 series exhibits similar characteristics.

As to your second issue, I am not sure but I think this may be the adaptive transmission control. There seems to be a lot of confusion on how this works, but basically if the transmission is in normal automatic mode it monitors your driving behavior to set one of the various gear shift timings based upon how it "thinks" you drive. If you are driving very mildly and then all of a sudden hit the accelerator hard, the X5 seems to not think you are serious and sometimes takes a little while to kick in. If you have "recently" been driving aggressively the transmission seems to respond right away. The general principles are clear, but I have not seen anything official anywhere that states exactly how many of these submodes there are (within both normal and sport automatic) and how long or exactly under what conditions the current submode is stored before adpating to a new submode. I should note that I have had times where the acceleration took a few seconds to kick in normal automatic mode, but never in sport mode. Perhaps this is because sport mode always assumes you want your acceleration immediately or because I intrinsically drive more agressively in sport mode.

Sorry for the long winded response, but both of these issues bugged me as well and I only found scattered, incomplete, and often inconsistent responses to both of them.

I hope this helps. Most importantly I hope you enjoy your X as much as the rest of us do. No car is perfect. To me the net sum is still VERY positive.