I have read every thread on here and still don't know the best answer. I live in SLC, have a 2011 A6 Coupe, the only mods so far are Airaid intake and Borla axle back exhaust. I want to do a basic stage one upgrade with the upper pulley, injectors, and tune. We only have 91 octane available here, the pulley recommendations range from 2.45-2.55, what is best in this environment? At this point I do not intend to modify further but will go with the bigger injectors just in case. What is the best pulley size and why?