My new Echo trimmer calls for 89 octane fuel and explicitly says no more than 10% ethanol. No disputing that ethanol and small engines don't play nicely, but the 89 octane surprised me. Do I really need the 89? I usually just load up the big jerry cans with 87 when I'm putting gas in the car and mix up a gallon of 2-stroke gas for the snow blower or weed whacker.