Full speed. The sports button does affect suspension and throttle. But not the sports transmission. The button pressed definitely makes the suspension stiffer and the car more responsive and agile.

So...

Sport OFF - less jumpy off the line and a softer ride for the wife and kid?
Sport ON - when you are by yourself testing out the "driving machine" handling and performance?

I keep my sport button on all the time. All I notice is a stiffer ride and better handling. I feel nothing as far as throttle response.

Craig

That's pretty much the conclusion I've come up with.

But I must say. This might be only for the 4.8. As I went to test drive a 35d and I played with the sports button and didn't notice much in throttle difference (though I was quite distracted with the sales guy who kept talking and pressing the sports button off when I pushed it on).

With the 3.0, maybe it's not the case either as it sounds like the throttle response on it is slow to begin with. (From another post stating that you need to step on it half way before you really feel the car moving. That was something that put me off during my test drive of the 3.0)

This would make sense from all the conflicting posts.

^ well the slow response is the same initial lag that people with the 4.8 report. The same lag that other thread indicates other late models like the 5s have.

On another note, most other vehicles have an overdrive button, which saves fuel with taller gears. Usually it is kept on unless you want a more responsive, sportier throttle... basically the concept is opposite of what most of us want because our sport button is usually on. So I don't think an overdrive equivalent is what BMW had in mind when they put in the sport button and there are way too many conflicting opinions here (sport pkg = always on stiff suspension, throttle only, suspension only, etc.) to really conclude anything. I would tend to believe the manual in that case - the button is only available with sport pkg correct? Adaptive Drive - only tweaks the chassis & suspension:

http://img188.imageshack.us/img188/3728/sportmr.th.jpg

The initial lag as described above sounds very reminiscent of the lag reported by M3 drivers, myself included. FWIW, it is due to the drive by wire throttle. Usually occurs when coming to a rest and then sudden heavy throttle. The computer sometimes gets a little caught off guard and checks all sensors before opening up the throttle. Thus the momentary lag followed by a surge of power.

Its completely different and no way related. I started the thread at m3post that now has some 42,000 reads and 900 odd posts on that subject.

I've owned both the x5 and m3 dct. The lag issue on the m3 dct transmission is completely different to the apparent lag you get in the x5. The x5 "lag" is no different from what you get in typical automatic transmissions.