I have recently bought S60 which came with 235/40R19 summer tyres. I am already late to change the summer to winter tyres. when I asked volvo they gave wheels of 235 /45R18 for around 1700 euros which I found was so expensive. Now I asked a big car repairing centre in our region and they said 1200 euros for winter tyres with 225/45R18. They checked few times if it fits this model and confirmed it. They said in winter it us always better to have lower size because of aquaplaning. Since I am new to this changing tyres and not so tech savy, I thought of getting few suggestions from you guys. Is it okay if I go with 225/45R18? Does someone have experience with this lower size? Please help.