True, the manual 4Runner is gone forever but the mileage is actually better than what you've heard - I managed 25 US mpg City driving with the X5d and I drive entirely too fast. On the highway, 35 mpg is pretty common, and a full tank can go for about 500 miles.
As for the extra cost, yes a diesel always costs more, just like a turbo or supercharger does, but I, for one, would be happy to pay an extra $3k for all that torque, which would seriously alter the performance characteristics of the 4R and make towing so much better, probably making it superior to the old V8 for towing, and putting it close to a 7,000 lb capacity.
That, to me, is what the 4R should do, and if the partnership with BMW means a diesel will come sooner than later, then bring it.
More, the take rate on BMW's diesel X5 is growing year over year, with more than 30 per cent of buyers now opting for the oil-burner, suggesting Americans are finally warming to what most of us have known all along.