Just a quick note for anyone looking at buying part worn winter tyres.
"Manufacturers and tyre safety organisations generally recommend replacing tyres when tread depth reaches 4mm; with winter tyres, the role tread plays is even more pronounced. In an official release, Continental quotes the advice of one Ruprecht Müller, an expert at the technical centre run by the German motoring organisation ADAC: “The tread pattern makes a crucial difference, especially on snow and slush,” stated Müller. “A winter tyre loses much of its traction on snow in particular when the residual tread depth drops below four millimetres or so. It makes good sense to replace the tyres at this tread depth at the very latest."