While E85 might not have been the magical panacea its original proponents envisioned, in 2023 it is one of the most popular fuels for performance applications. Between its low cost and high octane number, it has been proven time and time again to be able to support insane power levels. And the real kicker is that it’s available straight out of the pump.

The fuel has really changed the marketplace, so much so that we see fuel manufacturers, like BOOSTane, now manufacturing and selling their own E85 fuel. It might seem odd to hear the name of a company that got their start with a pump-fuel enhancement product manufacturing fuels, but it’s actually quite a logical step. BOOSTane’s founder, Ian Lehn, is an engineer by trade and a racer by heart. Combine the fact that he’s a chemistry nerd and a racer, and now you’re starting to see how the company BOOSTane came to be.

So, when he started manufacturing his own “drum E85” (along with four other race fuels) our interest was piqued — especially given some of the conversations we’ve had previously, and the fact that his original line of products, BOOSTane octane boosters, were designed to circumvent the need for high-octane race fuel. “We fulfill a pretty unique niche in our market [with BOOSTane] as far as performance fuels are concerned,” says Lehn “But at our core, we always wanted to support the grassroots effort, and E85 is very much anchored in grassroots. It’s a high-performance fuel that is pretty widely available.”

There are a lot of components to a fuel to give it its overall octane rating and one of the main components contributing to the octane rating of E85 is the alcohol itself.  — Ian Lehn, BOOSTane

BOOSTane’s E85 Race fuel is a combination of 85-percent ethanol and 15-percent 98- to 100-octane race gasoline, which makes for a potent, reliable high-performance fuel.

However, it’s Lehn’s reservations about ethanol in general that made us want to pick his brain about the product. “For a long time, I was vehemently against ethanol — I’m not saying that I’m the biggest fan of it now, either,” Lehn says. “There’s a lot of drawbacks to tuning and using E85. I mean we even see problems with E10. So I was very resistant to [E85]. I developed other additives to help stabilize it while increasing the octane; developing products for E85 that go with it. But ultimately if we were going to [develop an E85 fuel] we wanted to come out with a product we are proud of.”

BOOSTane E85 fuel specifications

That ethos led to the development of what the company has dubbed “E85 RACE” — a name that hints at a few of the deficiencies of pump-E85 that BOOSTane is addressing with its E85 fuel. “E85 has an inherent octane value to it that is better than pump fuel,” says Lehn. “There are a lot of components to a fuel to give it its overall octane rating and one of the main components contributing to the octane rating of E85 is the alcohol itself. The combustibility is not bad, but the latent heat of evaporation is what really cools things off. It’s pulling heat out of things that inherently build heat.”

Our first experience with BOOSTane’s E85 RACE fuel was on the 2022 Giveaway Twin-Turbo Godzilla engine, where LME used it exclusively in the testing.

Lehn also points out that E85 isn’t without its faults. “There are some things that you have to be aware of with E85. By definition, it’s hygroscopic so it has an affinity to absorb water out of the atmosphere (as well as fuel lines, rubber seals, etc.). That’s not only going to cause a phase separation in a drum, fuel tank, or in a carburetor, but also increased wear patterns that you might not see with another fuel. So, it can be a double-edged sword. If you know what you are getting into, great. There are ways to mitigate the risks, but you have to be aware of the issues.”

What’s Coming Out Of The E85 Pump

While Boostane does make products to help battle some of the inherent challenges of an ethanol-based fuel, The E85 RACE fuel primarily aims at solving one of the more egregious issues facing users of E85: inconsistent (and sometimes subpar) chemistry. First and foremost is the actual percentage of ethanol that is in E85. To be legally called “E85” at the pump, it only needs to contain between 51- and 83-percent ethanol. Depending on whether it’s winter or summer, your blend can also be affected.

In a trust-but-verify scenario, you should be testing for ethanol content every time you fill up from a pump. If you run a flex fuel sensor with multiple ECU maps for different ethanol content, you’re probably OK with not testing. But, if you are tuned for a specific amount of ethanol, a surprise drop in ethanol content at the pump can lead to all sorts of issues with your tuneup. Consistency in the blend is actually one of the largest benefits of buying E85 by the drum. You know that you are always getting a consistent 85-percent ethanol.

Flex Fuel is not designed to be a performance fuel out of the pump. It is designed to be an economical, sustainable fuel. While blender pumps like this one aren’t super common, regulations allow for anywhere from 51 to 83 percent ethanol in products labeled “E85.”

And then there is the quality of what is coming out of that nozzle that you have to deal with. “When you get quality differences out of the pump, it’s the blend percentages,” says Lehn. “Typically the ethanol component will be of a standard quality, since it’s actually a quite-involved process that takes a lot of energy, and there aren’t a whole lot of refineries making the ethanol component themselves.”

So, while the quality of the ethanol component isn’t really worth worrying about, batch to batch, station to station, the other “15 percent” (which can be as much as 49 percent, legally) can be bottom-of-the-barrel distillates. “You have to think about where E85 [at the pump] came from,” explains Lehn. “Flex Fuel was designed to be a cheap, renewable alternative to traditional long-chain petroleum. Keeping that in mind, with all the subsidies, they are going to put the bare minimum into the fuel to get it to work. It’s not intended to be a high-performance product. So, there’s no need for the added cost of a good gasoline component for the big refineries.”

In addition to using a high-quality ethanol component, that always makes up 85 percent of the fuel, BOOSTane’s E85 uses the good stuff for the 15 percent as well. “In BOOSTane Race E85, that 15-percent is race fuel. It carries its own octane value in the 98-100 range,” says Lehn. That high-end component acts as a safety buffer in the overall formulation, compared to the low-octane barely-able-to-be-called-gasoline component in cheap, pump E85.

U.S. Department of Energy, Handbook for Handling, Storing, and Dispensing E85 and Other Ethanol-Gasoline Blends; page 6, table 3. Here you can see the allowable variances in pump E85.

Making The Right Choices

When all is said and done, only you can choose what fuel to run (or a sanctioning body, but that’s a whole different can of worms). If you are looking at E85 for what it is, and not expecting it to perform miracles (you won’t be replacing an intercooler by running E85), using a high-end performance-formulated E85 makes a lot of sense, as the Flex Fuel coming out of a pump has a whole lot of allowed variance, and was designed to be an inexpensive, renewable resource.

BOOSTane has expanded beyond just octane booster and fuel additives, offering five different race fuels in everything from a 5-gallon pail to a 220-gallon four-barrel skid. They are E85, 109-octane unleaded, 110-octane leaded, 116-octane leaded, and a UTV-specific 96-octane fuel.

E85 will allow you to make more power than gasoline, and do it for less per gallon, compared to equivalent other fuels. However, due to the 30-percent lower power density, E85 requires extra fuel system capacity to make the same power as gasoline, along with specialized ethanol-safe components. Besides the hardware, E85 needs some extra care and attention due to the fuel’s characteristic of pulling moisture out of everything it touches, be it the air or fuel system components, and then being deposited where moisture doesn’t belong.

At the end of the day, if you’ve made the choice to run E85, then like everything else we work with in the hobby, it only makes sense to use the best options available. We used the BOOSTane Race E85 in the Giveaway Godzilla engine build, and that thing made 1,000 horsepower way more easily than any of us thought possible. In that test, the fuel wasn’t even a variable in the equation, it just did its job, and allowed the tuner to do his.

The final dyno of the twin-turbo 7.3L Godzilla engine. It only needed 7 psi to make an easy thousand horsepower. We had plenty of room to make more, both in the fuel and in the turbos, but the owner wanted to stay conservative.