I don't have a gas auger but I know alot of the small engines won't run on 87 anymore. My weedwacker this past spring wouldn't run so I tore the carb apart and cleaned it, put it back together tried it pop, stall, nothering, repeat. after 2 hours of this it finaly occured to try 89 mix and no problem since. A month later my cousin calls me about his lawn mower(with a 4cycle Briggs engine) won't run now I know where to start drained the gas fill it with 89 second pull this thing ran like new.Stihl says right on thier oil mix containers to only use 89 octane.