I reckon it is quite usual to drive with DTC off with 3-series but 5-ers? How many of you drive with DTC off and your experience? All BMW cars are perfectly balanced so this switch means something like serious / fun to me.

 

There are three position in 1, 3, 5 and 6 series:

1. DTC on, DSC on (normal)
2. DTC on, DSC restricted (pressing shortly DTC/DSC button)
3. DTC off, DSC off (pressing more than three secs DTC/DSC button)

Now, to which one of these are you refering to?

 

Whats the difference between DTC and DSC? What do they do?

 

ones for traction, the other is for stability (roll overs) ? i think

 

DTC - Dynamic Traction Control - controls wheel spinning up to a certain speed (IIRC 40 km/h)
DSC - Dynamic Stability Control - controls the stability of the car at any given speed

Two completely different things. BMW confused us a little by playing with the button label, starting with DSC and then labeling it DTC. But from origins to now, the button does what I listed above in steps 1, 2 and 3.

 

No, not roll overs. DSC controlls ANY stability correction, like understeering and oversteering...

 

I recently had the 550i on the track. Driving with DTC and DSC on was frustrating. However, with DTC off and DSC on, it allowed me to power through turns, however if I over did it the tail will start to come loose and if I kept increasing power the DSC would come in as I was starting to slide sideways more.

 

I started driving with DTC off (short press) recently and noticed that the car feels lighter. I also noticed some slight skidding going round roundabouts at speed in the wet, which was corrected by the car before it got out of control. It's more enjoyable with this setting IMHO but I'm not sure how long I can be bothered to get in and have to turn it off each time, especially stuck in traffic jams on my daily commute!

 

I'm referring to DTC off, DSC on which allows you to go sideways and slide on roundabouts, highways exits and other curvy occasions

 

Yeah exactly