[Fithian]

I have Bridgestone Blizzaks on my E92 335i RWD on 17" tire rack rims and they worked pretty well last winter on a 10k mile trip cross country with 2 weeks in Boulder. On the wife's previous car E39 528i 6-speed RWD 15", we had Hakkapeliitta studless tires which were fantastic on a cross country trip. On my previous E36 325i 6-speed RWD 15" we had studded Hakkapeliitta tires which were phenomenal on glare ice and snow.

Better winter performance is achieved with a higher aspect ratio. The E92 had 225x45x17 snow tires. The E39 had 55 series, the E36 had 60 series.

We will be picking up an F10 535i RWD with sport pack in September. This comes with 40 and 35 series 19" wheels; not good for snows. Standard wheel is 18" and possibly 17" which would be much better for snows. Check with Tire Rack in October for possible wheels and tires.

It might seem reasonable to change tires on the original rims each winter, but do the math. Around here (PA) it costs about $30 to have a tire mounted and balanced on a wheel. That's $240 for a season and there is the possibility that it may cost a lot more due to the run flat tires. Considering the cost of new wheels ($100 ea), sensors ($50 ea), and tires ($150 ea) (mounted free), and the option of selling the set at half off when you sell the car, it is probably more economical to buy the set.