Picked up Style 210 wheels and 255/55R18 Michelin Latitude X-Ice Xi2 the same day I got the X5. Been a great combination in heavy snow. Style 209 would work also and both are the "BMW recommended fitment" wheels and tires for snow. I actually like the 18" wheel design more than the 19" Style 335 that came on it, incidentally. I don't have fender flares.

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8/2011 X5 xDrive35d Sport, Black Sapphire Metallic, Black Nevada Leather, Fine Burr Walnut Trim
2/2001 M5, Jet Black, Exclusive Complete Black Walk Nappa Point Heritage Leather, Black Cubic Trim