As mentioned in a previous post, do not conflate ethanol content with octane rating-ethanol may cause corrosion in older (but NOT newer) fuel injected engines, and low octane (regardless of ethanol content) can damage a high-compression engine. I have 5 bikes that take everything from 87 to 93 octane E10, so I just buy 93 octane E10 and fuel the bikes in my garage at my leisure.
On the other hand I use 90 octane E0 (widely available as "Recreational 90" or "Rec 90") exclusively in my Mercury Verado engines. The manufacturer recommends 91 octane E10, although the engine is smart enough to run on 90 octane without damage or noticeable performance loss. That said, with a 180+ gallon tank full of fuel that may sit for weeks at a time, having ethanol in the system won't help anything and could increase the chances of corrosion. In SW Florida, just about every marina offers Rec 90 exclusively for gasoline-powered marine engines.
Many gas stations in SW Florida carry 87 octane E0, which may be useful for older gasoline engines to prevent corrosion in the system. Check out https://www.pure-gas.org/ as a starting place to find what's available near you.
Last edited by shorelasHD; 07-25-2019 at 04:57 PM.
Reason: typo
There are 3 stations within about 4 miles of my house that carry non-ethanol gas. One carries 89 octane, another carries 91 octane, and the other carries 93 octane. I've used E10 in my old Ironhead plenty of times and it seems to run ok on it, too. I just don't leave it in the tank for long periods of time, though.
Of those options, 93 is best. If a pump doesn't have the exact recommended octane, go up. Higher is less efficient, but lower could lead to cylinder knock that could actually damage your engine. The only danger of higher-than-recommended octane is wasted money and possibly wasted gas that didn't ignite from lower compression.
I saw a few pumps in Wyoming and Utah that were called "Clear Clean" or something like that. It was ethanol free, but I did not try it in my truck. IIRC, it was priced about the same as Premium blend but was only 88 octane. I could be mistaken.
John
Yup, it's only 88 octane here in UT. A few places here and there might have something different, but you kind of have to seek it out, and at that point, who cares anymore. Just get some 91 and be done with it.
FWIW I tried the 88 E Free a few times, got knocking in the engine so that was the end of that.
07-25-2019, 04:55 PM
