W also has a taller reverse gear so that you can back up in low traction conditions. W limits shift points compared to S, typically not allowing higher than 4500rpm shifts, as well as upshifting a little earlier on light throttle shifting.

__________________
John Shellenberg
1998 C230 "Black Betty" 240K

http://img31.exs.cx/img31/4050/tophat6.gif