I know that 225/45/17s are not a recommended size for snow tires, but does anyone actually have them on? If so, how are they?

 

I have 225/45/17 winter tyres on the rear wheels of my 8, and 205/50/17 at the front because they were left from my wife's previous car, a Boxster. The main noticeable parameter is the car is a bit lower and the bottom of the 8 sometimes hit the protruding stone gate stop.
I intend to move to 215/50/17 when I need to renew my winter tyres.
You had any question in particular?

Fabrice

 

Nope, no question in particular, I just wanted some piece of mind. I just bought 4 of them because thats all that was in stock. I got a really good deal on the rims. Are the tires wearing unevenly? I will probably switch to 225/50/17 after these wear out simply because that is the recommended size.

 

well the first thing is you really don't need a 18inch snow tire theres no point... the second thing is you want a narrower wheel, think ice rally cars.
More weight distributed over a smaller surface area will help you dig down deeper into the snow/ice/sleet/whatever, hense more traction. Larger sidewalls are also good but not nearly as important.