Higher octane always is good. However on stock not as much impact. Just allows for less timing to be pulled by the dme in less than ideal conditions.
I had logs from the v4 days when auto tuning was turned on. Man on 91 octane the boost and timing would either stay level or drop based on conditions. When I had nearly all 104 in the tank the boost increased and timing dropouts were non-existent (outside of the 4300 rpm Vanos shift).
I'm a firm believer, hence everyone's use and love for methanol injection.
Last edited by forza1976; 03-03-2012 at 11:52 AM.