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Can We Mix E85 Flex-Fuel with Regular Gas? (Explained)

Spending so much money each day after fuel really makes us wonder if it’s actually worth it? Recently, the popularity of E85 flex-fuel is increasing in the market.

E85 flex-fuel seems like a better option as it is much cheaper than regular gas. E85 contains 85% ethanol and like natural gas, it does not burn as much fossil fuel.

However, it is not feasible to use only E85 flex-fuel. So, here rises a question. Can we mix E85 flex-fuel with regular gas?

Can we mix E85 flex fuel with regular gas?

We can mix E85 flex-fuel with regular gas in different proportions but only in a flex-fuel vehicle. Using it in a gasoline vehicle will reduce performance and eventually increase your cost. E85 is cheaper per gallon but it is not really cost-efficient as ethanol burns much faster than gasoline.

E85 contains 51 to 85 % ethanol. It is very efficient in terms of energy as burning ethanol emits greenhouse energy rather than the emission of fossil fuels.

It is highly encouraged to use E85 flex fuel along with regular gas as it is cheaper and more sustainable.

Mixing E85 and regular will result in less fossil fuel getting burned and at the same time using e85 on flex fuel vehicles increases the performance of the vehicle.

A flex fuel vehicle can run on up to 85% ethanol. You can mix any proportions of E85 flex fuel and regular gas and your flex fuel vehicle will easily adapt to the mixture.

It is not recommended to use E85 in gasoline-based vehicles. Doing so will result in poor performance and your engine might turn off after the fuel starts to burn.

What happens when you mix E85 Flex-fuel with regular gas?

Any proportion of E85 can be mixed with regular gas and the flex fuel vehicle with adapt to the percentage mixed. Mixing E85 flex fuel with regular gas is beneficial. Given below is what happens when these two are mixed together.

Better performance:

Using E85 flex fuel with regular gas increases the performance of flex fuel vehicles. It generates increased horsepower and torque. The correct proportion of the mixture is good for the engine.

A cleaner environment and more sustainability:

E85 is up to 85% ethanol. Burning flex fuel produces fewer greenhouse gases, unlike regular gas which burns fossil fuels.

Mixing them will be beneficial for both the owner and the environment as it is sustainable and reduces the emission of fossil fuels into the atmosphere.

Less mileage:

Mixing E85 with regular gas reduces gas mileage compared to using only regular gas as ethanol burns a lot faster than regular gas.

Even though more gallons of E85 are needed per mile than regular gas, the cost of ethanol is also less so, it eventually balances off.

How well does e85 mix with regular gas?

It mixes well as long as we are using a flex fuel vehicle. It’s equipped with electronic sensors which can adjust the blend and make any changes required using its microprocessor. A flex fuel vehicle can have 10 to 85% ethanol.

So, you can use any combination of ethanol and gas and the flex fuel vehicle will run just fine because it mixes very well.

Maintaining a frequent proportion is good for the engine as the microprocessors will adapt to the blend more easily.

E85 mixes so well with regular gas that it gives you the opportunity to pick any sort of combination percentage and it will still be able to blend correctly.

Does E85 burn faster than regular gas?

Yes, E85 burns faster than regular gas. This is because E85 contains around 51 to 85% ethanol and ethanol burns a lot faster than fossil fuel.

E85 flex fuel lowers the gas mileage it consumes more gallons of ethanol per mile compared to regular gas.

Ethanol burns fast because it is oxygenated which means it contains oxygen. The oxygen in ethanol reacts with the oxygen in the atmosphere and gets vaporized fast.

On the other hand, regular gas goes through a slower combustion process so it increases the mileage.

In terms of cost, it does not really matter because even though more energy is consumed per mile due to using ethanol, the cost of ethanol is also cheaper than regular gas.

How to mix E85 fuel with regular gas?

As we know, there is no one way of mixing E85 flex fuel with regular gas as it can be mixed in any proportion and the vehicle will blend it properly.

You can follow these steps to know how E85 flex fuel is mixed with regular gas which increases the octane rating and also reduces the cost at the same time.

Preparing E85:

The first would be definitely preparing the ethanol for the E85. The raw materials of ethanol go through 5 steps before becoming pure ethanol.

These are conversion, fermentation, distillation, filtration, and dehydration. After that the ethanol is used to make E85 within is 85% ethanol and 15% regular gas.

Adding the proper amount of gasoline:

As much as gasoline you wish can be added but adding the repetitive amount will give the microprocessors of the engine time to get familiar with the proportions and it’ll blend in easily.

Perfect proportions:

50% ethanol and 50% regular gas are a good proportion for your flex fuel vehicle. Adding 5 gallons of 91 octane pump gas and 5 gallons of E85 will produce 10 gallons of 96-octane.

The 96-octane is very close to E50 which is 50 percent ethanol and 50 percent regular gas.

What are the benefits of using E85 fuel?

There are numerous benefits of using the E85 fuel only if your vehicle is flex fuel. Here are some of the advantages which make E85 one of the best fuels for consumption.


E85 contains ethanol. The combustion of ethanol reduces the contribution to greenhouse gases compared to fossil fuels.

It reduces the emission of some toxic pollutants which are emitted when natural gas is burned and replaces those toxins with water.

It is much healthy and safer, making it an environmentally friendly option.

This is a major advantage as comparing the number of vehicles on the streets every day, a huge number of greenhouse gases get released if only regular gas is used.


Using E85 in flex fuel vehicles enhances the performance generating increased torque and horsepower.

It can easily burn any proportions of fuel that has been added. It runs smooth and keeps the engine healthy for a longer period of time.

It has the ability to resist compression and detonation increasing the rate at which the engine works.

Cheaper by the gallon:

Even though it burns faster than regular gas the cost of E85 per gallon is much cheaper. It is not at all expensive compared to the large number of benefits it produces. It is safe to say E85 flex fuel is cost-efficient.

Corn plants:

Corn plants can remove carbon-di-oxide from the atmosphere so it is possible to grow them for E85. This reduces the bad impact E85 had on the surroundings and balances off.

So, technically E85 is very little harmful to the environment compared to regular gas.

Does using regular gas in flex-fuel vehicles harm the engine?

No, using regular gas in a flex fuel vehicle does not harm the engine. The flex fuel vehicles are designed to run on regular gas or any gas as a matter of fact.

The vehicle is built using advanced technology which can adapt to the blend of gas or any particular gas and makes necessary changes.

Using pure gasoline gives a better gas mileage as regular gas does not burn as fast as ethanol.

Keeping in mind the octane rating of the vehicle there is no harm in using regular gas in a flex fuel engine as it is literally built for the usage of different types of fuels.

What does the number in flex-fuels mean?

The number in flex fuels means the percentage of ethanol present in it. For instance, E85 has 85% ethanol and the rest is gasoline. E50 has 50% ethanol and the rest is regular gas.

The number refers to the percentage of ethanol and gasoline blend which is important to be acknowledged by the user.

Final thoughts:

To sum it up, we can easily mix E85 flex fuel with regular gas-only in flex fuel vehicles. In regular gasoline-based vehicles, it is not possible as E85 cannot be used there. Other than that, mixing E85 and regular gas is highly encouraged as it has a lot of advantages.