4.8is vs valvetronic 4.4
 

I've never driven a 4.8is but i'm worried that in acceleration it could have the same problem of the 4.4 valvetronic I drove time ago. It was so demoralized.
I previously drove the 4.4 2001 and was really amazing start from 0 to 100km/h. With the valvetronic starting from traffic light was not so fun.
Is the 4.8 the same?
Thanks

Interestingly, I recently ordered a 4.4. It accidentally got taken off the production line and sent for emissions testing, so I was given a 3.0 loaner. The 3.0 was really zippy and fun. When my 4.4 finally arrived, I was very disappointed because I had the same experience as you. Very poor acceleration. It just felt heaver and much more sluggish than the 3.0 I also thought it was the valvetronic after reading several threads. Turns out though, at least in my case, its the transmission. If you use manual shifting, the car is anything but sluggish and is amazing! It becomes very apparent that its the way the tranny is responding. Try sport mode or manual. You will see the difference. Unfortunately, I have no idea how to improve response in automatic mode. Maybe BMW did this to improve fuel economy?

Doesn't the 4.8is have valvetronic too?

Actually, thinking about this prompted me to call my service dept. They said it is a completely different tranny in the 3.0 and 4.4. A ZF? vs a GM. Said it is the tranny difference that gives it the different what they called "feel".

GM makes the 5-speed Steptronic, not the 6-speed

The 4.4 valvetronic is noticeably faster then the 3.0 varient of the X5. The 'feel' is just that, it feels like it isn't moving fast enough. In reality, its moving plenty. I can't speak directly to the 'feel' of the 4.8 but with a 0-60 nearly 1 full second faster then the 4.4, it has to be fast.

Surly the 4.8 is faster than the 4.4 of 1 second, but I was speaking of sensation: not so funny like the first model. Maybe like "dcast1" sayd, the 3.0could be faster at the first sensation( I have never test the 3.0 it, but I can agree with him).

The 3.0 probably just feels lighter on its feet, but the 4.4 and 4.8 show brute strength in acceleration.

Exactly.... the transmission governs which mode the car drives in. The longer you drive it (especially if you are a conservative driver) the more conservative it becomes as it 'learns' your inputs. A 5 series owner has found that up to a second can be lost in timed runs depending on how conservative the trans are. Short answer is drive it like you stole it............

I've tried the 3.0, the 4.4 and the 4.8. Indeed a good crisp inline six with a nice manual gerbox is a very different sensation from a V8 auto; even though in real terms the V8 may be pushing you faster. If "Sensations" is high in your vocabulary, You should try a remapped 3.0diesel with manual tranny.:) Can you say "Catapult" ??