Do you know what the maximum temperature an ice auger will ever achieve is? Its about 160 degrees above ambient temp - no more. Assuming a 0 degree F day, that means an ice auger at max load ran at wide open throttle for 45 minutes is never likely to exceed 160 degree engine oil. Hardly a place where 30 or 40 weight oil is needed. And again, I don't think you understand viscosity vs temp, at all and why 0W20 is actually ideal in these engines, and the 0W40 recommendation is off base.