"Best" is subjective some people prefer certain brands over others. Then you have to decide what size of wheel to go with (18" are recommended) and then if you want to go with runflats or non-runflats. If you want to stay with runflats Dunlop Grantdtrek WT 3M. Non-runflats Pirelli Scorpion Snow & Ice. Alternative non-runflat would be Dunlop SP Wintersport. If you decide on non-runflats throw a can of puncture seal in your trunk or get the BMW tire repait kit or the Airman puncture seal kit comes with pump and sealant.

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2013 BMW X6M-current
2013 Audi S4-current
2007 BMW X5 4.8i (E70)-sold