First came the inevitable internet leaks of model codes, then some astute Swabian in a distribution warehouse made a few Euros with some iPhone shots of brochures. Then came the speculation - fuelled by impish dinner-time chat between BMW engineers and journalists on product launches late last year. "Ja, we have a tri-turbo diesel motor: it's going to be amazing!"
Okay, this mighty powertrain will arrive here in the X6, but I struggle to consider that a motor car at the best of times, even more so when the prospect of the rather attractive new F10 5 Series with a 545lb ft diesel motor has just been announced and, hours later, denied. Four-wheel drive or two-wheel drive, there will be no M550d or xDrive for the UK. Occasionally we are denied truly desirable motor cars because of our RHD needs. I still yearn for a LHD E38 740d. It doesn't happen very often, but this is surely the biggest kick in the goolies for many, many years. As a touring with 4WD it might just have been my ideal car.
Move along, nothing to see here
Or would it? Two years ago I ran a 535d Sport Touring for a while. It was five years old, pretty ratty and it went like the clappers. It also never returned more than 30mpg at a cruise. Heaven help me I tried - coaxing it around like Silas Marner's minicab-driving brother - but it just wouldn't deliver. And if I actually used the performance available, which was hard to avoid with some crazy twist forces present the moment the crank turned, it fell into the mid 20s - sometimes lower if I was 'making time'.
Now I really, really enjoyed living with that car, but one day it occurred to me that in becoming a genuine slugger, the diesel powertrain had rather skewed away from the basis of its own existence: fuel efficiency. In the 535d I wasn't actually enjoying any great advantage in fuel economy over a similarly driven 530i - instead I was enjoying a different type of performance delivery. One I hasten to add I really enjoyed and found perfectly suited to squirting past slower traffic.
These new tri-turbo BMWs are good news because they prove that the company remains determined to deliver something more than the competition and, it has to be said, more than is strictly necessary. Mercedes has no answer for these monster diesels, and the 309hp/479lb ft Audi bi-turbo V6 suddenly looks a bit weedy.
I can't wait to get a go in an M550d in Europe, drive it fast back-to-back in the company of an M5 or an E63 and uncover the real-world differences in mpg. These new turbocharged petrol engines with stop/start hardware are so efficient compared to their predecessors, I'm not sure the difference will be that great. BMW claims 37.7mpg on the combined cycle. You have to wonder if anyone besides Miss Daisy's valet will ever see such a figure.
Truthfully, I am gutted we will miss out on the potential splendour of the M550d. We Brits will just have to make do with the F10 535d - an excellent motorcar which, I've recently learned, can always be 'mapped' for greater things. (Ducks for cover)