M+S doesn't mean they're any good as winter tyres. Anyone can put M+S on their tyre - there's no minimum grip standard, testing, or anything required. The SP20 doesn't appear on the Scandinavian Tyre and Rim associations list of approved winter tyres, and isn't marked with the snowflake.

Take a look at the BF Goodrich MT tyres, also M+S marked, and compare to the SP20 and see how different they are. That's how much use the M+S mark is.

M+S and the snowflake are two different things. Tyres with the snowflake usually also have M+S, but many tyres are marked M+S but have no snowflake because they aren't winter tyres. I know that S stands for snow. And M stands for mud, so not sure what that's got to do with winter tyres. Try driving with BFG MT (mud terrains) on winter roads and you'll see what I mean. They will be quite good on deep fresh snow, but not on average winter roads that are usually hard packed snow or ice. They don't display the snowflake. Neither do Cooper STT - also M+S, or Goodyear wrangler MT.

The swedish traffic office warn of this. "OBS! Det förekommer däck som är märkta med M och S utan att vara särskilt framtagna för vinterkörning, exempelvis grovmönstrade terrängdäck" Translation - There are tyres labelled with M and S without being specifically designed for winter driving, for example rough textured terrain tyres.

M & S on a tyre's like heavy duty on a battery, it don't mean a thing.

I've got a couple of identical tyres on one of my motors, bought at the same time. One's marked M&S, the other ain't. Are they different compounds?

Well told you. Again this morning a faultless performance on the run into work.

I drove up hills past stuck cars floundering around on summer tyres in my old X-Trail. Three inches of snow on ungritted roads -no problems.

Dunlop GrandTrek ST20's - Mud n Snow tyre - original equipment on the X-Trail and worth every penny. Only if you actually want to get there that is.