S - Standard
This position is used in all normal driving conditions.
W - Winter
The car will pull away in 2nd gear - unless the throttle is fully open or the selector lever is in position 1 (S).
Traction is easier to control in 2nd gear.
Traction and driving stability are increased on slippery surfaces.
Gear shifts, both up and down, are made at lower road and engine speeds than when the programme selector switch is in position S, even when the throttle is open.
Read more:
http://wiki.answers.com/Q/What_is_the_S ... z1akDOEAKtP.S. Google pwns^^