Despite success stories with a size 315 winter tire, I'm just too nervous to run that size. I live and drive all over upstate NY where you can have all 4 seasons in one day, and lake effect storms can drop a foot of snow in a couple hours. I am on the road constantly, and need a winter set up that can handle anything. I went with a square set up of 20" x 10" Ace Convex wheels shod with 275/40/20 Nokian Hakkapeliitta 7 studded snow tires. The weight of the X5M, the X drive, and these studded snow and ice eating monsters makes this the best winter vehicle I have ever driven by a long shot. When I bought the M, it came with a set of 19" Pirellis on the tire rack wheels, and I was very disappointed in their performance. Very underwhelming for a dedicated winter tire. Plus, I wasn't a big fan of how they looked.
I ordered the wheels in a square setup with a 74.1 mm bore and 35 offset, so they are hubcentric in the front but need a ring in the rear. I did this so I can rotate the wheels, and so that if I decide to sell them they will fit on all X5's and X6's. In the attached pictures, I have a 25 mm spacer in the rear, but it still looks a little tucked with only 10" wheels. I am awaiting delivery of a custom 40mm spacer that will be hubcentric to the smaller rear hubs on the M and hubcentric to the wheel.
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