PSM on snow - On or Off

[Actus Reus]

Simple question really - the cars in question are a 997.1 Targa 4 and a 987.1 Cayman S - on snow would you leave PSM on, or turn it off? I was always under the impression it should be turned off, though a BMW employee is arguing with me saying I should leave it on? He's a bit of a tt though.

[Trev450]

Yes as above really. You need to use it dependent on the situation. If there is reasonable traction to be had then probably best left on. If on the other hand traction is poor then switch it off as momentum can be lost waiting for the PSM to cut out.

That said, however, with winter tyres fitted I haven't yet had to switch the PSM off in any circumstances.

[Dr S]

I run Winter tyres and always switch off PSM on snow. I find it extremely intrusive and killing the necessary momentum for smooth progress. I'd rather have the one odd moment of oppo

[Actus Reus]

That's always been my opinion, though I've very rarely driven either of the two Porsches I've owned on snow as I've always had the use of something else - until this year.

The wife's company Audi went a while ago and so the Cayman is our only car for now, hence my question, especially as we live at the bottom of a fairly steep hill. Most of today's snow seems to have thawed now anyway...

[BubblesNW]

Last year I drove my 996C4 in some fresh snow from Sheffield to Manchester via the motorways as the cross-Pennine routes were closed. PSM saved me a couple of tmes when the back end let go at low speeds.
However, after stopping on a hill I needed to turn off the PSM as the complete lack of traction resulted in the PSM cutting the pwer. PSM off and a good boot of gas resulted in steady progress up the hill with plenty of gentle fishtailing. Once back on the flat PSM was re-engaged.

[uknick]

Never tried it with winter tyres, but in the snow my Cayman is useless going up even a very slight slope, unless I have nearly new tyres at the back.

[Sunnysidebb]

Off....as the DME will keep pulling power if the wheels start to spin. With PSM off it allows the wheels to spin so at least some progress can be made. Also as the rears spin this does send more torque to the fronts.
Our drive is about 50 mts long and on a slope. In the Snow, once its been compacted a few times then frozen , my 6tt would only ever get up the drive with PSM off.