all that means is that they're going to have to bump up the hp in the V8...and there's always going to be someone who would rather have an 8 cylinder over the 6 in our bigger is better society.

Maybe BMW will wait for the new twin turbo V8?

Honestly I think they will just dump the twin turbo engine for MY08'. They can't afford to lose sales to the MDX...

Either that or MY08' will be a short year, and they will begin MY09' early (in march versus july) - a typical practice when BMW transplants a new engine into an existing vehicle line up (07' 3 Sedan & 06' 5 Series which both did this).

I always though the rational for the twin turbo configuration was keeping the weight of the engine down...makes less sense to me in an X5 than a 3 series. Having said that I reckon it must be much cheaper for BMW to have one engine which they can offer in normally aspirates, single and bi-turbo variants than developing engines of varying sizes.

Actually, you guys are all looking at it the wrong way. A BIG HEAVY SUV like the X5 really needs TORQUE to get this tank going. Yes, I agree a 50 hp doesn't sound like much of a difference, but I am willing to bet that the 3.0si's 225 lb/ft torque vs. the twin-turbo I-6 with 300 lb/ft torque makes a BIG difference!!

As someone pointed out, the 5-series for model year 2008 in the U.S. will have both the 535i and 550i.

However, I am more interested if BMW will release a X5 3.0sd, not just the X5 3.0d, but the sd!!

The 3.0sd is a twin-turbo diesel engine that has 286 hp and about 414 lb/ft torque!!

You are right the sd would be a beast... My parents would pick one up right away..!

you're right, but how big of a difference will be felt between the 300 lb/ft on the I6 TT and the 350 lb/ft on the 4.8i? I guess that is the question...if they come out with the 3.5 TT engine for the X5, would it be worth it to get the 4.8i with only a 50 lb/ft difference, but with an approximate $8-10K difference in price? (based on the difference between the 535i/xi and the 550i)

Thats where the new twin turbo V8 comes in... :)

isn't that model suppose to compete with the cayenne turbo and ml63? if that is the case, what is going to compete with the cayenne s and the ml500 if the 3.5 TT competes with the regular cayenne and ml350?

The new 7 series will get a twin turbo V8 ala 335i + two cylinders as its vanilla plain engine.

Then there will be another engine that slots above that to compete with the AMG's, Turbo S's...

I see...I always thought that the V8 TT was going to be the "is" engine. I'm sure this has been discussed before, but maybe they'll use that V10 they have from the M5 and M6.