Snow tire setup

[mkarch]

Go narrow. You didn't say what vehicle they're on, but if it's 2WD you'll notice the lack of traction from wider tires enough that saving a hundred bucks on 225's is not worth the compromise. On AWD it might not matter as much.

[IShootNikon]

Yes, I"m going with 205. Thanks

[Parsec]

What type of car is this? Many dealerships sell OEM winter wheel packages so you can check what size they offer for your car. For example my OEM tires are 235/60-18, but the manufacturer offers an OEM winter wheel package that's 235/65-17 which is practically the same size.

[IShootNikon]

Lexus IS250, OEMs are optional 18" staggered wheels

225/40/18 on fronts and 255/40/18

205/50/17 and 225/40/18 are identical diameter sizes. 225 are just wider