Run premium in it (I get mine from Costco) and if it doesn't ping, then great. If it pings, I guess you have some choices: a) octane booster; b) avgas; c) racing gasoline; or d) back off the ignition timing.
If you're looking to avoid ethanol, check out
Ethanol-free gas stations in the U.S. and Canada In Ontario, Shell V-Power, Costco 91, Canadian Tire 91, Esso 91 and Ultramar 91 are ethanol free.