[KeepingItReal]

Originally Posted by Best2bgolfing

Any automotive person wort there salt will tell you that the up-charge is not worth it. The golf cart engines are designed to run on 87 octane fuel. What the ethanol attacks is the fuel lines,pumps and any rubber item. Not the engine. The marine additive is nice but not necessary. Fuel lines can be changed at the house for about $15.00 in 10 years, are we Ok with this!!!!!!!

Ethanol actually lowers the octane, the extra cost is worth it if you can get it, pay now or pay later. Phase-separation will sooner or later damage the engine.

Gasoline Octane and E10 Ethanol Blend Fuels

PURE ethanol has a very high octane, about 114, but many mistakenly believe that E10 conventional gas sold has "extra octane" then stated at gas pump.
Regarding octane and E10 gas, buying sub-octane gas is more common, then "extra" octane.
Since ethanol is considered an octane enhancing additive, if/when E10 sold has less than exactly 10%, the result will be sub-octane gas (less than number stated at the pump), AND,
When E10 gas phase-separates (high octane ethanol drops to the bottom of the tank with water), the upper tank layer octane typically drops 2.5 points. E.G. 87 octane gas purchased now becomes sub-octane 84.5 gasoline. E10 gas is available in all grades, including regular-87, premium-91, racing-014, etc.
Testing a fuel sample from tank bottom for alcohol percent will confirm gas contaminated with water, and is not safe for use.

After phase-separation upper tank layer typically drops from 10% ethanol to 0-2%, and lower tank layer typically test 60-95 percent alcohol (can/will damage engine).