After driving my '99 Z3 coupe in northern Colorado last winter with its MXM original tires, I replaced them last month with 225/55-R16 MXM4 M/S tires. Much better on snow-packed roads due to improved tread design and compounds used. I may leave them on all the time as they handle on dry roads about identical to the 225/50 MXM tires but are more compliant over bumps. Plus the actual speed over the ground is closer to what the speedometer says.