Snow tire options

[mclawrence]

it looks like im without my ix this winter so i need opinions on wheel size for snows.im in the midwest and will need to use my e30ic as a second car and dont have any snow tires at all.i have a spare set of stock weaves for the ic 14" and a spare set ix 15"s.its most important the best size wheel for the ix long term
both cars are stock height and my options are
1. buy/mount snows 14" for ic this year and then use for ix
2. buy/mount snows 15" with spacers for ic this year and then use for ix
also what size spacers would you need to run ix 15"s on a stock e30?

thanks for any help

[nando]

13-17mm would work