auto a6, 3.15 and 26" or 28" tire?

[jblaze2004]

NA auto a6 guys


I have a automatic 2014 mustang gt premium with 3.15 gears. Only mods are lethal offroad hpipe, roush axle backs and LUND tune.

What would be the best tire diameter to use as of now?

and


Best tire size would be 28" or 26" if i decide to go cobra jet intake kit?

 

[Blazer707@TBR]

Personally I like a 28inch tall tire on these cars.