Carb components have been tweaked over the past few years to deal with the ethanol, so just go to the local gas station and buy the darn gas. If you don't have a ZDZ, MVVS, or 3w there's no point in anything more than "regular" unleaded. If you have a ZDZ, MVVS, or 3w then buy the premium. It's that simple and requires no rocket science thought processes to carry it any further.

Av gas contains lead and our engines don't benefit from lead. Lead was required in earlier engines that had real valves and seats. There was a change in valve train components quite a few years ago that eliminated the need for lead. In fact, you may find yourself with lead fouled plugs if you elect to spend $5.00 plus a gallon for low lead av gas.

You guys worry waaaaay too much!