Best fuel
Based on my experience, GOOD fuel or the BEST fuel is one that provides the most protection. The needs to be a good blend of castor and synthetic. typically fuels that exhibit such qualities will coat the Piston and headbutton with the dark brown to black film. The quicker the fuel does this the better the fuel is. Odonnel is good, I have not ran the new Byron blend so can't comment, however the one that I do run, J-Tech racing fuel, I have found to be the best. It remains un affected by Cold weather as low as (I live in FL)37deg temp or high 90+ degrees. Most important to me is that it is consistent form batch to batch.