Re: How long does it take gas to go bad?
BillP, the reason the street racers use high octane is not because it makes an engine go faster, it is because they have higher compression engines, many of which have been modified to higher compression by the owner, and higher compression engines require higher octane. Some of these guys will retard the ignition so that they can drive the beast to work Mon-Fri on cheaper lower octance car gas. Then on Sat nite they advance the ignition to the best position, put in the higher octance gas (aviation or other) to prevent detonation, and realize a perfomance boost commensurate with their high compression. Octane in excess of the requirement for the particular compression ratio and ignition advance for a given engine will not under any circumstances provide additional power and may in certain circumstances lessen it.