In Reply to: It's the tread pattern and rubber compound that... posted by gercar on October 08, 1999 at 04:58:24:
Not all BMWs come with all-seasons, and the exceptions are not only the M cars. For example, the E46 sport package comes with performance tires. The sports package on the 5 series does as well.
So, the 17" are fine if the tire is designed to work well in the wet and given that all BMW OEM tires are all-season (except the M cars) 17" should work as well in the wet as the 16".