You are misguided. There is no need to boost the octane of E0. Your breathing is harmful to the environment, but I wouldn't suggest you stop..
I am misguided by the data I've personally collected that have concluded exactly what's in the chemical makeup of E0 and E10? The data were the mileage results of my carburetted 2000 ZX-9R motorcycle are in correlation to AFR readings coming off of my wideband UEGO Lambda gauge? Huh? They're repeatable results and easy enough for anyone to verify, so if anything, they are deductive in theory. I make no secret of those results and I stand by the data and its conclusions.
Continuing on OPs subject. I am providing more details that anyone can freely look up about refiners' fuels, blended fuels, and "
sub-octane" (E0) fuels (typically 81 - 84 AKI E0). The
US Energy Information Administration -
EIA has an informative PDF on how refiners use 110-112 octane ethanol (E98) to modify their "sub-octane" E0 fuels , boosting its minimum octane rating cheaply (yes, subsidized).
Perhaps some will appreciate this little tidbit too. Since E0 is typically such poor grade fuel, termed by the industry as "sub-octane," in order to meet "minimum octane ratings" for regular, mid-grade and premium fuels at the pump, all of which will be rated as E10 (
up to 10% ethanol), regular will have the least amount of ethanol octane modifiers as a percentage and premium will have the MOST ethanol as a percentage. Meaning, 87 AKI may be 95% E0 and 5% ethanol, whereas 91 AKI premium will have an ethanol content of something higher than that, maybe 93% E0 and 7% ethanol.
We know that water is a corrosive. We know refineries do not pipe ship E10, but instead pipe E0 fuels to distribution wholesale terminals, where E0 is blended with ethanol and shipped to retailers. Mid-grade fuels in between those of regular and premium are typically "blended" at the gas station dispenser in whatever ratio necessary. For instance, 50% 87 AKI E10 regular dispensed at the fuel pump with 50% 91 AKI E10 premium, results in 89 AKI mid-grade E10, without the need for shipping or storing 89 AKI separately.
So its not as easy as just filling up. And as I mentioned originally. It's a fools errand if you rejet a carburetted engine for stoich on E0, regardless of AKI rating, then attempt to run E10 through it. Don't do it. Your engine is not EFI and cannot determine fuel lambda. The AFRs will be off-the-chart lean and you could damage your engine.
Another consideration for ethanol-free proponents in Summer is running 100% E0 in an EFI vehicle equipped with a narrow-band lambda gauge. We know E10 has less energy in it and that ethanol burns slightly cooler than E0. EFI computer controlled vehicles that only know whether a mixture is rich or lean based on lambda and adjust fuel-injection according to that, will typically run a mixture of ~14.7:1 AFR on E0. That mixture will result in the maximum amount of combustion heat, which is exactly what my two data sets resulted in negatively or positively. That is the energy efficiency of E0 at stoich. It is capable of producing more thermal expansion through heat than E10...obviously.
Here's where the trick comes in though. An EFI vehicle with a narrow-band gauge, however doesn't see AFR, it only sees lambda a measurement of when 'a fuel' is stoich. So if you've filled your tank with 100% E0 because your truck will be towing a loaded 5th-wheel or your touring motorcycle will be carrying you and the wife and all of your gear for a week and you want the most engine power, your computer will be telling your vehicle's fuel injectors to maintain the hotter and leaner 14:7:1, where E0 is stoich. And on a tank full of E10, they'll be producing a slightly richer ~14:1:1 with the relatively cooler ethanol flame front, where E10 is stoich, due to the oxygen atom ethanol brings with it. In other words, if you're the guy with E0 in your EFI vehicle's tank, you'll want to make sure your vehicle's cooling system is fully functional.
And consistent with this, is if you own an EFI track bike with a wide-band UEGO and Power Commander and the fuels available to you are ethanol-free or ethanol blended E5 - E15 fuels, you'll definitely want to run the highest octane E0 race fuels your computer controlled ignition system can handle, ones your PC can take full advantage of. Gravitate towards the E0 fuels and away from the ethanol enhanced fuels, if horsepower is what you're after and your cooling system can manage it.
Continuing with what I've researched and consistent with all of the above about E0 v. E10, if you have a carburetted lawn mower you own at your house in Santa Fe, NM, and you follow other people's online advice blindly and fill it with E0, because hey, who doesn't want their lawn mower to run its best, right? You're going to quickly find your lack of understanding about the subject has left you with egg on your face. E0 does not bring an oxygen atom to the AFR party, because it has no native additives that have oxygen atoms. So while you're neighbor's identical lawn mower is happily cutting grass throughout the summer next door running E10, your lawn mower may start then stall once warmed up, will probably be belching a lot of black smoke unlike his, struggling to cut your grass in the thin hot Summer air, and unable to reach the RPMs of your neighbor's mower. That has something to do with manufacturers tuning their small carburetted engines for
reliable sea-level operation on E10, not E0 (see fool's errand). Combustion is a chemical process that requires semi-ideal conditions to occur. You could rejet to take advantage of E0, but if you're like most people, you haven't and you are putting in E0, which has no oxygen atoms in it and you're depriving the motor of atmospheric pressure (air), during Summer's heat, it's going to be choking on fuel molecules it cannot chemically oxidize. Which is why I ONLY run E10 in all of my small carburetted motors. None of them have been rejetted. Instead I've used the float-bowl height trick for a relatively leaner mixture for higher top RPMs and more grass cutting in Summer and snow-blower snow blowing power in Winter.
I live > 2,000' AMSL. E10 is what the engine's were tuned to run on by the manufacturer and it's the only fuel they've been refilled with for the two or more decades I've owned all the them (less tests to experiment with E0). E10 is my goto fuel for best operation and coolest operation for my internal combustion engined vehicles for year-round use. I have the choice to fill them with E0 at any time, but all of my motorcycles and small ICEs are jetted to run best power AFRs on E10 where I live, which makes them incompatibly jetted to run with E0. Zero failures and zero problems with E10. You guys are free to use what you think works best for you. I'll be sticking with what my vehicles prefer and allows them to run relatively cooler, for longer reliable operation, E10.