Winter Tire Sizes

I am getting winter tires for the first time on my 2012 Mk6. I found some wheel/tires on Craigslist for a good price but the tire size is 215/55 R17. Right now I'm on the stock 225/40 R18 Detroits with all stock suspension. Anyone know if I'm gonna run into any issues if I run the 215/55 R17 as winters?, aside from the speedometer being off a few mph. Thanks!

Those are pretty big

You want 225/45/17

I wrapped some Falken all seasons (205/55/16) around some steelies, and they were great for the 2 winter seasons I actually drove my GTI in New England winter conditions.

Since I dropped 2 inches in Rim diameter versus stock, I went with a 55 AR, and the car went through snow and potholes without a hitch.