The Importance and Responsibility of Running Ethanol (E85)

The importance, and responsibility of running E-85

Before ethanol, there was a time where for those of us who made substantial horsepower numbers, we relied solely on race gas. Let’s travel back to this time pre-2006 when the sport compact scene was very alive and well with brand new Subaru WRX and STI models rolled off showroom floors, along with Mitsubishi Lancer Evolution models. Almost every state had a well-functioning drag strip as enthusiasts raced in whatever they had just to feel the rush of their newly installed mods, and how they improved their times. 600+ horsepower was considered massive at the time, and you could only see those numbers out of MKIV Supra turbos, or fully built Hondas running giant turbochargers with faucet-like injectors to feed the cylinders.

In this period, we relied on race gas to make these numbers safely and sustainable. We either had leaded 100 or 110 octane, and we had a variety of options from VP Racing Fuels such as their C-16 race gas or VP import, which also made for an awesome cologne. Behind the scenes in the world, was an insidious turn of events. We had the war in Iraq and Afghanistan that funneled an unquantifiable amount of money into the military industrial complex, private security, government contracts, and along with whatever conspiracies you can think of. Additionally, virtually anyone could buy a house as subprime mortgage lenders threw approvals at anyone’s laps. This meant that people making small salaries got into larger homes, and people were refinancing their homes to keep up with the jones. The war greatly effected oil production and corporations along with their venture capitalists all came to collect. The result was the economic collapse of 2008. Some of you who are old enough to be in the workforce during this time will never forget these times. During 2008, gas prices reached well over $4 which was astronomical as average salaries were a little lower, and people were losing jobs and foreclosures were happening at recor levels.

CRAZY. WHAT DOES THIS HAVE TO DO WITH ETHANOL?

The 2008 astronomical rise in gas prices drove fear into masses, and economic strategists did not have a clear view or prediction for what was to come. This innovated automotive manufacturers to revisit the idea of Flex Fuel. Now Ford introduced Flex Fuel in the 90s in their Taurus models as oil companies were starting to introduce ethanol in their gasoline production because ethanol comes from corn, which is a biomass because it is grown in large farmlands, and is naturally renewable. Ethanol is used in small percentages because it oxygenates the fuel. It takes less energy to burn ethanol in a combustion chamber, and it is cheaper than gasoline. So, during 2008-2009 when we experienced extremes in gas prices with uncertainty, Ford and Chevrolet reintroduced Flex Fuel in their larger SUV models that were known for not having the best in MPG. This also meant that production in ethanol went into overdrive with gas stations introducing E85 at their pumps, which at the time, was a about a dollar or so less than a gallon of regular unleaded.

YAY FOR CHEAP RACE GAS!

Mad scientists of the racing community quickly discovered that you could make more boost and more power with E85. In the beginning, the main discovery is that to run ethanol, you needed more duty cycle out of your injectors, and a larger fuel pump to push the ethanol through, along with higher fuel pressure. Tuning was also needed to run ethanol as you had to play with the ignition timing, fuel tables, with running upgraded larger fuel injectors. It was discovered that tuning was a little more challenging simply due to the lack of stand-alone options and setting ethanol up to run with piggyback systems with a general lack of experience also created some hurdles. However, once enthusiasts and their respective tuners were able to iron things out, the results were very impressive at the least. Depending on the actual ethanol percentage in E85, the octane rating floated from 100-105, and this was an amazing discovery because at these times, a 5-gallon pail of race gas was around $60, and with E85, you could fill your tank for much less than $60. Additionally, ethanol was discovered to lower carbon emissions which was better for the environment. So, we had US-grown corn resources, as well as E85 stations quickly becoming more established across North America. This is just too good to be true right? There’s always a catch. What was the catch?

WHY IS EVERYTHING FALLING APART IN THE GAS TANK?

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Ethanol does not behave like gasoline. For many automotive consumers of ethanol, it was treated and utilized just like any other pump gas method. Find the station that has ethanol, pump, and go. But after longer periods of time, and especially after winter storage, many discovered issues with their vehicles not being able to start or being difficult to start. We experienced clogged fuel filters which was strange. It was discovered that the problem began in the fuel tank area where we would witness in horror all the debris floating within the fuel, and how much debris had settled into the bottom of the tank. And after siphoning gas tanks and cleaning all the debris out, the problem persisted inside the fuel lines and into the injectors. Turns out, ethanol is not only highly corrosive, but will quickly degrade rubber.

Ethanol breaks down traditional automotive rubber materials and will make it brittle and crumble into pieces. For those of us who used rubber couplers to hold together and isolate more than one fuel pump, the rubber would break apart. Rubber fuel lines would internally degrade into little pieces traveling into the fuel filters, and the micro debris would eventually ruin injectors. Fuel injectors would also leak because ethanol would eat away rubber injectors and injector grommets.

Even auto manufacturers that made flex fuel vehicles also experienced the same problems for consumers that fueled their vehicles primarily with ethanol to combat the high fuel costs. Because of these reasons, the automotive and fuel manufacturing industry went into overdrive to figure out a solution. And the solution was employing rubbers, plastics, and metals that were ethanol resistant.

And it wasn’t just limited to making rubber ethanol resistant. It was also discovered that internals of fuel injectors needed to be enhanced to work with E85, as well as fuel filters because ethanol would eat away certain powder-coats or anodized finishes where the debris would also clog injectors.

WHERE ETHANOL CAN MAKE YOUR SUBARU VULNERABLE

Bottom line, E85 or ethanol blends are high maintenance. Corrosion occurs on modded Subarus, or any vehicle for that matter that use ethanol but are not driven on the regular. Cars that get driven bi-weekly or occasionally, are the vehicles that will mainly experience this problem. And even if you have fuel pumps that are ethanol-friendly, fuel lines made of PFT or Nylon, along with the rest of the fuel system you can experience issues with injector O-rings which can cause leaking.

K, I DON’T WANT TO EVEN RUN E85 ANYMORE WHAT’S THE POINT?

Hold on there, Carl. There are some things you can do to make sure that you prevent corrosion buildup. The point of this is to make you aware that if you start experiencing issues within your fuel system, it may be due to ethanol, but you need to have the right stuff to employ it. We can help guide you on some extra steps you can take so that you can run E85 safely, you just need to stay on top of maintenance.

And with that said, E85 is not for the set-it and forget it type. Unless you’re okay with filling up the tank and drive until something needs replacing. There are some precautions and upgrades you can perform to keep your engine and fuel system happy when running ethanol. With that being said, here are some obvious, and not-so-obvious suggestions when running ethanol.

MAKE SURE YOUR FUEL SYSTEM IS FULLY PREPARED

Most of your fuel system components within your fuel system must be E85 friendly. Otherwise, you will experience misfires. This is because rubber, plastic, or other debris will clog your fuel filters first, before making their way into your injectors. Here is a list of some of the items that you must have when running ethanol:

Fuel Pump: Running ethanol requires a higher volume to push the fuel towards the engine. Additionally, the internal and external construction of the fuel pump will be made to sustain ethanol.
Injectors: Like the fuel pump, your injectors must be tuned to run a higher duty cycle when running E85. And the internal components are less resistant to ethanol.
Fuel Lines: There are fuel lines that are made using ethanol-resistant rubber, PTFE Teflon, and nylon or stainless-steel lines made specifically for E85. OEM rubber lines after prolonged use will become dry, will break apart inside, and will eventually ruin your fuel filters and injectors. Note that for those of you using PTFE lines, they use a specific fitting and insert specifically designed to work with PTFE.
Fuel Filter: You need a ‘bio-content’ fuel filter which can handle all fuels. And the majority of aftermarket fuel filters of today, will be ethanol safe to use.
Fuel Pressure Regulator: Like the pump, injectors, lines, and fittings, the fuel pressure regulator must be ethanol friendly. Now most will be, but older units will have an internal rubber bladder that will corrode with ethanol. More importantly because you need a higher volume of fuel to run E85, the pressure must be tuned to a reasonable psi.

FLEX FUEL MAKES YOU KING OF THE CASTLE

Companies such as COBB Tuning make a flex fuel sensor for those of you who do run E85. Flex fuel is such a luxury especially for those of you who regularly use E85 in racing circumstances and must know the overall ethanol content. Why? BECAUSE NOT ALL ETHANOL IS CREATED EQUAL. This means that every station that you acquire your ethanol from, has a different percentage of ethanol content. On average, most stations have about a 70% ethanol rating. But the most important parameter to pay attention to, is that if your car is tuned on 70-80% ethanol, you could risk damaging your engine if you filled up your tank with ethanol that has a 65% ethanol rating. If you don’t have any tuned fail safes, you could risk leaning out the engine. With flex fuel, you have a sensor that measures the level of ethanol in your fuel system which will send signals to your ECU so that your plug-in EMS such as the COBB Accessport or your standalone EMS system can make the appropriate adjustments in boost, timing, and fuel trims to accommodate the changes. Additionally, flex fuel allows you to run both pump gas and ethanol which is very important, as it is good to run straight pump gas every other fill up as regular gasoline can help clean or flush any corrosion buildup in your fuel system components. And it is highly important that if you store your vehicle for the winter, it is best to store your vehicle on pump gas with a fuel stabilizer as having your car sit for a while with ethanol will accelerate corrosion, as ethanol does have a shorter shelf life when compared to regular gasoline.

YOU’RE GONNA NEED A TUNE DUDE

If you made the proper fuel system upgrades with more importantly, larger injectors, you’re going to need a tune because E85 requires more volume and injector duty cycle. E85 runs cooler and requires a larger quantity of fuel for combustion and to achieve proper air/fuel ratios. For COBB Accessport users, there are some off-the-shelf MAPS available that will work with E85, and experienced tuners can also integrate E85 through a flash tune or through a standalone engine management system.

YOU MUST STAY ON TOP OF OIL CHANGES

For those of you who run E85 daily, your oil changes need to be more frequent because fuel contaminates oil. Example, when you start your car, your injectors spray fuel into your cylinders as the spark plugs ignite the fuel to create combustion. It is normal for fuel to settle on the pistons when done driving, and the fuel can make it passed the piston rings and into the oil. So, another example. If you start a car when cold, let it run for 20 seconds then turn it off, you will have more fuel in your cylinders because most cars are tuned from the factory to run more fuel when the engine is cold to help get the engine to start. If you start a cold engine then immediately shut it down, then attempt to try to start it again the engine will struggle because the cylinders are flooded with fuel. The reason why you must wait to start the car again is because the fuel evaporates, or drips passed the piston rings and into the oil.

The point is, with any regular gasoline that gets into the oil whether if you flood the cylinders or if you are running rich, the heat will eventually burn or evaporate in the oil. With ethanol, because it takes more fuel volume to burn ethanol, most of the time as many of you E85 users know, E85 struggles to start especially when outside temps are cooler. The reason why you must change your oil more frequently on E85 is because unlike regular pump gas, ethanol contaminates your oil and can turn it into this gelatinous consistency when the oil is cold. It’s not like regular gasoline that can evaporate or burn off with heat in your engine, ethanol can dilute your oil which can affect lubricating functions, as well as viscosity which can lead to damage. For those with dedicated race cars, changing the oil every 1k miles on ethanol is standard protocol, while for those of you with daily drivers should change the oil every 2k-2500 miles.

WELL, THIS IS A LOT. WHY EVEN BOTHER?

Hold on a second, our high-horsepower engines love ethanol. And everyone knows someone who has run ethanol and has never had any problems, and this is very true. Ethanol just requires more maintenance, and users need to be mindful of your fuel system components. With ethanol, something is bound to give at some point just like any wear and tear item on your vehicle. If ethanol is your only source of fuel for your Subaru, then it would be a good idea to change the fuel filter every year, while inspecting the fuel filter socks on the fuel pumps to make sure they are not clogged. Otherwise, your fuel pumps would be working harder to get the fuel to your injectors.

OKAY THEN. MOVE OUT OF THE WAY, HORSEPOWER HERE WE COME

Now that some of you are more aware of what it takes to enjoy E85 in your Subaru. We do carry a great selection of ethanol-friendly fuel system components to either renew or upgrade your fuel components to be ethanol-friendly.

COBB TUNING Subaru NexGen Stage 2+ Flex Fuel Power Package 2019-2021 Subaru STI