I know some will disagree, but I agree with Esox. The reduced volatility of premium will just make it harder for your auger to start in the cold. Wit the correct oil mix, your auger should run as good as it is ever going to on regular. Look at what the manufacturer recommends; if it ran better on premium, don't you think they'd say so? It's not like you're going through 20 gallons of gas a weekend and they're scared you'll be worried about the cost difference between reg and premium. It has to do with compression ratio, piston dome shape, quench area, ignition timing and other variables that just aren't an issue in an ice auger.