I have been experimenting lately with traction control ON/OFF in my x308 and DSC selection ON/OFF my x350, and comparing transmission shifting and throttle response with different settings.

Both default ON when the car is started.

I have noticed that with traction control disabled on my x308 and DSC disabled on my x350 regardless of sport / normal selection, rolling 1st gear clunky up/downshift issues totally disappear, throttle response is always immediate, and upshift/downshifts with various accelerations hard/medium/light is 100% smooth and deliberate.

However, with DSC or Traction control ON with dry roads, I do not get smooth shifting - especially noticeable is the rolling down/up 1st gear typically clunk down or delay up with Trac / DSC engaged, no smooth throttle response regardless of Sport/Normal switch across various acceleration types.

I realize that is all programming differences, but for my driving preference, Sport mode, trac / DSC "off "seems to give me the best acceleration throttle response and consistent shift characteristics.

I also wonder if Trac / DSC enabled shifting issues are causing people to perform troubleshooting that may be in some instances, wonky programmed throttle/shift issues with Trac / DSC enabled?

Of course when driving in wet/cold/snowy conditions I leave Trac / DSC enabled, but for spirited dry road driving I am really preferring TRAC / DSC off.

This topic will probably trigger all sorts of discussion on fluid changes/ types and levels, but when you answer with that, when shifting is absolutely perfect out of TRAC / DSC, consider that is not a fluid issue.

TCM is latest campaign on both cars.

Experiment for yourself and provide your experiences, findings, TSB's etc.