So what is it that requires the SVT to use premium?
Is it the slightly higher compression ratio over the standard V6?

I believe the SVT heads and cam are different, thus creating the .5 increase in compression...correct?

2000 WS6 Convertible A4 13.11 @ 107.5 with a lid, Ram Air and LTs Gone:95 Mystique LS Young America edition V6, MTX 15.6 @ 91