Tires make all the difference except when it is icy. Also some conditions where there is no ice on the road, but the road is covered with snow it can basically turn to ice with the pressure of the tires on the snow. Usually when there is 1/2" or less.

My X came with Continental DWS tires, staggered, and I have a 4.8l. No problems in the snow last year for me. I was really surprised how well the DWS worked. I am sure there are dedicated snows that may be better than the DWS, but I was happy with them.

Anytime the roads look questionable, I test them. Pull out of the driveway and make sure no traffic is around. I stab the brakes a few times to figure out what the road conditions are and how the vehicle will handle before I even get a few houses away from where I start.

My wife's E46 came with Continental Ultra High Performance Summer tires or something like that an it was rather scary to drive in the snow with those tires. They did not last long, compound too soft anyway, so I moved onto some decent Michelin All Seasons and it has been MUCH better.

Best to hit the tire rack web site and look at comments and reviews. You probably not need dedicated winter tires and wheels, you just need something far more suited for where you live and will be better in the snow.

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2008 4.8i Black with Tabacco. Black Y-spoke wheels and shadowline trim.