the price of gas fluctuating as it is, ive been wavering between low (87) and high octane (94) gas, and in terms of performance, there is no difference...however, on startup, there is a big difference: i have noticed that startup in very cold weather (now -20 C) the high octane starts on the first hit, the low octane is very laboured and requires at leasts two cranks.

this is hardly a scientific, just an observation.