Where i live we basically have three fuels, 10% ethanol, premium 93 mid91 reg87, the rockets run on 87 even the new ones with a higher compression ratio then the 2300s. Ive built my engine so 87 will work until i go thumping on it hard, it was tuned with pump 93 for 207hp, when you get above 10:5-1 compression ratio most builders are not running 87, on load, traveling weighed down, racing, stuff like that, detonation is bad, damage done.im currently probably 10:7-1 or higher, i had a time getting my cylinder pressure down to 210, if i had to on a rally put 87 in I would need octane boost to hoon, i might could limp to next station to get some premium 93, On my stock engine i run 93 not for the octane but for additive package shell adds. For me fuel cost has no factor on gas that i put in a motorcycle tank. I wanna keep it clean the best i can. I dont buy cleaners at parts store the premium keeps it clean, no deposits, black but no built up stuff ive found.