I run my Volvo S60 T5 on Goodyear Eagle F1 235/40Z/R18. We used to travel frequently to Germany in the winter and have carried snow chains for several years, although have never needed to use them. I know that these tyres are not good in the snow and last year did not use the car when the roads were bad. The tyres will shortly be due for replacement but with the low mileages we are currently doing I do not really want to buy two sets. The benefits of cold weather tyres in the winter make complete sense, but what would the downside be of using them all year?