Originally Posted by HighlandPete
That's how I drive (winter tyres), most of the time I've found you don't need to activate DTC, as spinning isn't the best way to move on snow anyway. Better to be very gentle on the controls and bite into the surface, before you make it more slippy with spinning wheels.
I disagree. The maximum grip level on snow is achieved at a higher level of slip than the car allows in the normal driving mode. That is why BMW has the Traction Mode (and that explains the name of the mode as well). I have been doing some testing with this, both around winter tracks and uphill. You accelerate significantly better with traction control disabled on snow. You can also go faster around corners with the car sliding slightly more than the car would otherwise allow.
I don't mean that you should be driving at the limit in public traffic, but using the Traction Mode will give you a bigger safety margin, since there is more grip available at the limit.
Ice is a different matter, and requires less slip, unless you are running tires with long studs, or the ice is very rough.