From the AA's website:
"Winter tyres give significantly improved handling and reduce stopping distances when the weather is cold (below 7C) and wet as well as when roads are covered in snow and ice."
I don't put them on the Supra, but have them on my other two cars, one of which is fwd and the other, rear engine rwd. When the ambient temperature is above 10C, they will feel a bit skittish, but I still put them on between November and mid March as the road surface temperatures are much lower than the ambient temperature, especially first thing in the morning.
On damp or wet roads when the temperature is