Without digging up the octane thread again, you can go 87 on your fuel if you want to tweek as it cools. Of course I am running a V92 so may be some difference but no pinging with 89 during the summer in high 80s/low 90s and running 87 now that we been back in the 60s again. Clean plugs, no soot in the pipes and following KevinX advice. Working for me with a noticable power increase as well as loss of the raw gas smell coming into a light or at idle. I am running stock NGK plugs with no issues.
2011 White Vision - Nuvi 550, Lowers, Lloydz 2nd filter, Vic perf filter, CB/Icom, 96 Brake LED's, Clear Signal lens/Switchbacks, VIC Hwy Pegs, Stebel Horn, 7Jurock 15" Shield, PCV, Lloyd ATS and Variable intake, Ness honkers
2004 V92 TC - S1 flash, level 1 slip-on, Ness big sucker K&N, ISO Grips, 4x1.5 Highway Hawg Risers, extra chrome (never too much), JM 2k CB 4' antena, Mustang seat, HD Front TS & Lowers, OD Pulley
Retired Navy SCPO