Here's my two-penneth worth...
I recently did some work for a very nice couple in the next village. Turns out he was marketing manager for Continental Tyres for donkey's years.
He fit's winter tyres to ALL his cars as soon as he gets them. He says that they work better all year round and give nearly twice as much mileage. He says that the British weather never gets hot enough to degrade the winter tyres during the summer, but work equally as well in the summer. They have a BMW 3.0D Coupe, Seat Leon Cupra and an Audi R8, all on winter tyres.
Here endeth my two-penneth worth.
:thumb2