MOst gases are formulated with the dreaded "E 10 or E 15" configurations. That means that, volumetrically, the refiners have either added 10 or 15% ETHANOL. EThanol is an additive that is supposed to "Grab" air pollutants in the same manner that SOme etheres were doing,(Until some wag discovered that Ethers , especially DIPE and MTBE were big time water pollutants). SO EThanol, which is actually BOOZE, is added to replace the ethers without all the secondary breakdown products (LIKE ANOTHER ALCOHOL) . HOWEVER, ethanol will **** up the plastics in your fuel line , mess up a carburator (If you have an old car that still has a carburator), and, it will grab any moisture and will set up a separate phase layer of water and crud at the bottom of your fuel tank. This will, in time , cause the engine to missfire, fail to start, and will mess up any lines and maybe even your exhaust manifold .
Ethanol formulated gas is every bit as bad (chemically) as the LEad formulated gas of our fathers day.
I search out "Conventional gas" as much as I can for my little Foprd Escape. "Sparky" my Escape, loves conventional gas and doesnt mind if I have to switch to an occasional tank of E10 gas, when I am far afield and dont have a Turkey Hill or some other local gas company around.
E10 will totally ruin any small gas engines you may have (lawn mowers, small or large outboards will die a painful death, and leaf blowers, chainsaws, etc)