I have a 2010 IS 250 AWD and currently in the market for winter tires. I am looking into getting the Michelin Pilot Alpin PA3 tires. My question is the size of my summer tires are 225/45/R17. I want to raise the car a little for winter driving. I was told I can put 205/50R17 tires on. I know having a shorter width is good for snow but how is it on dry pavement?

 

smaller radius???
no you'll have bigger radius by just a tiny little bit, imo 205's you mentioned are perfect for winter setup

go here http://www.1010tires.com/tiresizecalculator.asp
and play with sizes, you'll see what i'm talking about. you're still gonna be in spec and no issues on awd.

more important imo it's not going to be your 205 vs 225's setup, but a dedicated winter tire. like you said the alpins are nice, but also look at Nokians if you want some serious winter setup