The car has 17k on it, 4500 of which was done on snow tires and I'd say the tread is 60% worn (mind you the tread depth on the Dunlops when new is the lowest of any tire for the X5 on tirerack).

I'd bet we'd have a hard time getting to 20k mi. on the Dunlops, and I can only imagine how much of a problem they become in the wet when in their final months before replacement. Even now I think the X5's maximum speed with any water on the road (not merely a wet road, but rather collected water on the road) is about 15-20 mph lower than any other vehicle I've ever owned.

BTW, I've since had a change of heart about the Contis DWS. I've ordered the Bridgestone summer tires (Dueler H/P I believe) in non-run flat version. I figured 1) this is a heavy truck and for the handful of times I do push it, might as well have a max performance tire, since it is a sport pack BMW. But more importantly, 2) I think that a summer tire is still as good if not better in terms of aquaplaning resistance than an all season. Its easy to get confused with the ratings. I'm not concerned with wet grip (which is what tirerack rates - wet lap times etc..) I'm concerned with loosing control when I hit a puddle. Summer tires always have huge longitudinal aqua channels, whereas the all seasons have more complex maze-like treads. There is no data published that I'm aware of that speaks to how many gallons per rotation (however its measured?) a tire pumps out of its contact patch. Personally I suspect that the many biting surfaces that an all season has to help in snow does nothing to assist in reducing hydroplaning? But that's just my hunch.

I'll post some feedback when the tires go on.

Thanks for all the input.

DRP