Winter tire set-up on a 4.6is

[bimmian]

I am getting the 4.8is and need to get winters, I can find lots of great looking 8.5" wide rims with the required bolt pattern, 18" size and 40 offset, however, i cant find many with 8" widths.

My dealer says that 8.5 will be too wide, but i can see how thet are biased as they want me to buy the 8" ones that they have there. CAN ANYONE CONFIRM THE MAX WIDTH FOR ME PLEASE?

I am aware that narrower is better for winter, but .5" i dont imagine can make too much of a difference.

Thanks in advance.