A turbo diesel engine would be a great asset to the BMW US line, in perticular it would be a winner on the X5 and X3 SAV's. Moden diesels do not have the clatter that we used to have with these engines, and they have gobs of torque.
I for one would gladly trade my X3 3.0 for a turbo diesel, it would be nice to have the extra power and torque and at the same time go up from 16mpg around town to about 25 mpg.
Diesel fuel used to be cheap, but the oil companies have now got it up to the same price as gas. At least they can't screw us price wise with different grades of fuel, like they are doing with the gas. Bring it on BMW.