[jbee]

I Beleive the latest thinking from the rally scene is that studs (and by default chains - not that rally cars would use chains) give you less grip in snow. The best grip you can get in these conditions is snow on snow, so the more your tyres pack the snow into the tread and don't fling it out the better your traction will be. So take it slow and on't spin the wheels.

That said you still get fined in lots of places if you got there without them.