the s4 is a biturbo and not really that light the quatro system is heavy. i had 1.8t a4 and it was the most fun car too drive ever in the snow that is. I used to love driving thorough huge snow banks with it. Never did that car get stuck

 

Most of the chipped (w/stock k03's) only run in the 103-106 area w/o breather mods. They make fantastic torque though.....makes them feel quicker than they are. I'd say the Z, but in the 1/4 it is probably a toss up.

 

Yup