Is it OK to run E85 all the time? (2024)

Is it OK to run E85 all the time?

E85 is such an effective cleaner that some people run about 1 or 2 tanks worth of E85 through their engines instead of using a fuel injector cleaner. A surefire way to ensure that your engine remains clean is to use E85 often (or all the time).

Because ethanol attracts water it can create rust and seal breakage over time, and if E85 is left in the fuel tank for long periods it can attract more water vapor and potentially cause engine damage.

It can last years, or it can go bad in as little as three months. Its longevity depends on a lot of factors, including: The amount of moisture in the air. Whether the fuel system is sealed.

Using any octane level of gasoline in a flex-fuel vehicle is acceptable. The sensors in an FFV detect whether the fuel is pure gasoline or 85% ethanol and make necessary changes for optimal fuel injection and timing of combustion. Putting E85 in a car not designed for flexible fuel can be harmful.

E85 Cools Your Engine Better Than Regular Gasoline

It requires lower combustion temperatures. Also, it creates a thermodynamic cooling effect that regular gasoline doesn't offer. This is quite beneficial because E85 helps keep the engine cool. This helps keep the engine healthy.

Since ethanol contains less energy per volume than gasoline, FFVs will generally get 15%-27% fewer miles per gallon when fueled with E85, depending on the car and the driver's driving habits.

E85 fuel has a faster ignition time and flame propagation when compared to gasoline. This leads to higher cylinder pressure, as well as increased engine torque and power, gaining up to 20%.

The main disadvantage to using E85 is the fact that it's less dense than traditional gasoline. This means that your car will need to burn more fuel to get the same amount of distance compared to petrol, this works out to be about a 30% increase in fuel consumption.

Flex-fuel vehicles don't experience a loss in performance when using E85 fuel. In fact, some even generate increased torque and horsepower.

The drop in fuel economy is because ethanol has lower energy content per gallon than gasoline. E85 also burns faster than regular gasoline because it vaporizes faster. So your engine may eat through E85 faster than regular gasoline.

Is E85 bad in the winter?

Cold temperatures make this harder. So the colder the weather, the more time and energy it takes for ethanol to vaporize. Ethanol takes more time than gasoline to vaporize. This is why a car with E85 doesn't necessarily run or idle the best in cold weather until the engine is warmed up.

Ethanol doesn't corrode aluminum. It doesn't corrode anything unless the fuel is water logged. That shouldn't ever happen in a normal vehicle. Ethanol doesn't damage catalytic converters.

Ethanol has a corrosive action on fuel-system components, magnesium, aluminium and rubber. Running E85 on older model engines without tuning and replacing some components will ruin the engine in short time. Replacing fuel hoses, fuel pumps, gaskets, seals, fuel filters, fuel injectors, throttle bodies, etc.

E85 does get less mileage than regular gas, however, it's a matter of crunching the numbers, according to De Haan. He said if E85 is at a 20% discount or greater compared to gasoline, it may be worth it. The fuel can also run in short supply, and sometimes gas stations can have the pump shut off.

“So, every gallon of ethanol that gets blended comes with an RFS credit that is today worth about $1.50 a gallon," he says. "Some marketers and blenders are passing along some or much of the value of those RIN credits to consumers in the form of these lower prices. So that's why we're seeing E85. priced well below E10.

Right off the bat, any contest between 112-octane E85 and premium unleaded pump gas (91- or 93-octane) would be no comparison. The E85 offers more power, even before we get into the added ability to run more timing and/or boost from the lack of octane on the pump gas.

While ethanol does burn cleaner than gas, meaning less smog, flex fuel cars still produce roughly the same amount of greenhouse gases as their fossil fuel counterparts. Not as efficient. A car running on E85 has about 80% the efficiency of the same car running on gasoline.

Ethanol also has a higher thermal efficiency meaning when it does ignite, the temperature of the combustion is lower compared to pump gas. This allows a turbocharged engine to take more boost within a safe operating range without damaging the engine.

Ethanol has lower energy density than gasoline. That means you get fewer miles per tank of gas and reduced engine performance (e.g. less acceleration). Many drivers aren't thrilled about that. Finally, there's no compelling reason to burn ethanol over gasoline.

Back in the old days (pre-1994), E85 could eat away at some engine components. Most vehicles produced in and after 1994 are immune to ethanol. Since 1994, it has been US federal law that vehicles must be compatible with ethanol. So engine damage caused by E85 hasn't really been an issue since then.

How many MPG does E85 get?

What is the octane rating of E85 compared to gasoline? E85 has an octane rating ranging from 100-105, making it a high performance fuel. In comparison, regular unleaded gasoline has an octane rating of 87.

E85 (or flex fuel)—a high-level, gasoline-ethanol blend—is less volatile than gasoline and low-level ethanol blends and results in lower evaporative emissions. Tailpipe emissions result from fuel combustion in a vehicle's engine.

“It's OK to go back and forth. Cars are designed to use any blend,” Monte Shaw, executive director of the Iowa Renewable Fuels Association, says. However, he notes, it depends on the type and age of your vehicle. Flex-fuel vehicles can operate on gasoline that contains from zero to 85 percent ethanol (e85).

One other thing that you want to keep in mind is if your car has a yellow gas cap, that typically means that your car is E85 compatible - 85 percent ethanol - and you want to replace it with the same type.

Simply put, if you mix 5 gallons of 91 octane pump gas with 5 gallons of E85, you get 10 gallons of a 96-octane fuel that's very close to E50, or 50-percent ethanol and 50-percent gasoline.

The added boost of ethanol could increase the amount of smog-causing pollutants entering the atmosphere. Those pollutants can react with sunlight to create more smog — a big problem during sunnier summer months. Growing all that corn to make the fuel can potentially also result in more greenhouse gas emissions.

Using E85 in your vehicle without an E85-specific engine tune can quickly ruin your engine. That's because more fuel is needed when E85 is used. If you were to try to run E85 in an engine that was tuned for gasoline, it would run lean. Running lean can lead to serious engine damage.

Then add in the fact that an engine requires 30% to 40% more E85 than traditional pump fuel to make combustion–so that's even more cooling at work. “So anywhere ethanol evaporates, it's cooling,” Santner adds. Ethanol can make more power, too, since it contains more oxygen–about 34% oxygen by weight.

Does E85 smell different?

E85 tends to have sweeter smell. E85 is just great all around!

Ethanol has a corrosive action on fuel-system components, magnesium, aluminium and rubber. Running E85 on older model engines without tuning and replacing some components will ruin the engine in short time. Replacing fuel hoses, fuel pumps, gaskets, seals, fuel filters, fuel injectors, throttle bodies, etc.

While some might argue that using an alternative fuel source can negatively impact a vehicle's performance, in reality it can have the opposite effect. Flex-fuel vehicles don't experience a loss in performance when using E85 fuel. In fact, some even generate increased torque and horsepower.