If I solely drive in S+, with the intent of mpg's (short-shifting a bit), I can easily beat the economy of driving in D by about 3 mpg. Maybe more, if that was my goal.
I just can't stand normal traffic (not the @$$hat-driving idiots) pulling away from me at every light, so I try to just drive 'normal'.
FocusFest 2013: Best of Show
Gateway FFW: Show Class Outstanding
September '13 ROTM