Ethanol has become part of our daily lives in the regular fuel we put in our vehicles. The typical consumer is using E10 enhanced fuel, which is mandated by the EPA, and contains 10-percent ethanol. That ethanol has some important properties of concern to us in the performance world. For example 87 octane fuel, that is processed to the E10 standard, is actually 83 octane gasoline, the extra 4 points of octane to get to 87 come from the addition of ethanol. This holds true for 89, and 91 (or 93) octane fuels as well.
E85 is also increasingly popular within the performance community as “cheap” alternative to race fuel. While octane rating varies, E85 is typically good for somewhere between 100 and 105 octane. There are obvious benefits to this in high compression, or forced induction applications, chiefly it’s cheap high octane fuel at the pump, rather than from a barrel or race track.
The ethanol content in both regular pump gas and E85 is something that as enthusiasts and drivers we need to be aware of. Ethanol is derived from ethyl alcohol, it’s added to fuel as an oxygenate to improve emissions. Ethanol is also hygroscopic. This means it absorbs water, it can actually pull water from the humidity in the air. Combining oxygen and water often leads to corrosion on many different types of metal.
With these things in mind, it’s important to consider what you’re doing with your performance or collector car when you store it this winter, and what you may need to do to ensure you’re not replacing parts as often during the summer. Since ethanol is an alcohol based product, running this type of fuel requires many of the same considerations as running methanol, or another alcohol based race fuel.
Fuel system components, not designed for ethanol blended fuel are susceptible to the negative side effects of running it,” says Speed. “The higher the ethanol content in the fuel, the more detrimental the effects will be. -Lake Speed Jr, Driven Racing
The entire fuel system must be considered with any ethanol blended fuel. Viton seals, which are impervious to the degradation caused by exposure to alcohol are mandatory. Fuel lines should also be rated for use with this type of fuel, as should fuel pumps, regulators, rails, tank seals, and even the fuel tank itself.
Most mechanical fuel pumps weren’t designed for use with any type of ethanol at all, even just E10. The corrosive nature of the additive will actually cause fuel pump wear issues according to Speed. “We have found in our testing that zinc, magnesium, aluminum, and steel, the most common metals used in automotive applications, are susceptible to corrosion from ethanol.”
Zinc is used as an internal coating on most carburetors. During the chemical reaction with ethanol, zinc is used as the sacrificial anode, being corroded away, leaving zinc oxide behind. From there, the corrosion doesn’t stop, ethanol will continue to eat away at the remaining metal, causing further damage.
There is also the issue of the deposits left behind. Speed says With ethanol being bio-based, it’s going to leave more deposits behind. These deposits block passages in carburetors and fuel injectors, clog jets, and if left alone continue to build up and cause problems.
Fuel injected applications aren’t necessarily immune to these effects either. “Most people assume that modern fuel injectors are safe for use with ethanol. Unless the manufacturer specifically says the injector is manufactured for use with E85, you should assume it isn’t.” Speed also points out that in forced induction applications, where E85 has become increasingly popular with many enthusiasts, the additional heat generated can compound the issues of deposits and fuel deterioration.
Most people assume that modern fuel injectors are safe for use with ethanol. Unless the manufacturer specifically says the injector is manufactured for use with E85, you should assume it isn’t.
Driven Racing Oil has used their resources and experience in the racing world to develop the company’s Carb Defender product. Carb Defender protects components in the fuel system from the harmful effects of ethanol, without removing the ethanol itself. It also helps to clean up the deposits left behind. All of this is possible without changing the specific gravity, octane, or burn properties. The product is compatible with both carbureted and fuel injected engines, and the company is looking into an EFI specific version.
- Prevents corrosion and stabilizes fuel
- Keep fuel from going bad as quickly. The hotter and higher the pressure, the faster the fuel degrades.
- Deposit protection and control
- Oxidation stability
With winter setting in for most of the country, many of us are storing our project and race cars until spring, or planning our next round of winter upgrades. Before you close the garage door and pull on the car cover, it would be wise to run some Driven Carb Defender through the fuel system in preparation for your car’s long winter nap, and continue its use through the summer driving season to avoid problems.