Can You Use Regular Gas In a Flex-Fuel Car?

Automakers design vehicles to operate on different kinds of fuel. Some cars run on diesel while others operate on gasoline. Still, the tanks of some cars are modified to maximize the use of gasoline variations.

Therefore, if you own a flex-fuel vehicle, you might wonder if regular gas can be used. Well, flex-fuel vehicles are capable of operating on regular gas, but should you use regular gas in flex-fuel vehicles? This article discusses this and other related questions.

Here’s when you can put regular gas in a flex-fuel car

You can use regular gas in a fuel-fuel vehicle as often as you want without causing any damage to the engine or any drop in performance. On the contrary, regular gas will improve your MPG.

A flex-fuel vehicle allows you to use any combination of regular fuel or Ethanol: from 100% unleaded gasoline up to 85% ethanol. So if your car is low on gas and there is no ethanol station in sight, fill up at a regular station.

flex-fuel

What happens if you put regular gas in a flex-fuel car?

If you have mistakenly filled your flex-fuel tank with regular gas, do not fret, as it is very unlikely to cause damage to your engine. Although flex-fuel cars are designed to operate on fuels with high ethanol composition, using regular gas will not disrupt the engine’s function in any way.

These vehicles can smoothly switch between regular gas and flex-fuel. However, this is not the case with using flex-fuel (E85) in standard gas cars.

What happens if you put flex-fuel in a regular gas car?

A lot will occur to the engine if a flex-fuel is used in a regular gas car. Flex-fuels are not compatible with the engines of standard gas cars. Regular gas usually contains a small amount of Ethanol (about 10%) which is still compatible with the engine of traditional gasoline vehicles.

However, suppose the ethanol percent is raised. In that case, the vehicles’ engines bear the brunt as they try to compensate, leading to engine knocking, generation of strange engine noises, and other engine issues.

Flex-fuel, sometimes labeled as E85, contains a high amount of Ethanol, ranging from 40 to 83%, which is way higher than what standard gasoline engines can handle.

If you mistakenly fill your car with flex-fuel for the first time, you might not notice the effect on your engine if you act quickly. You can either decide to drain the tank, if possible, or use up the fuel while topping it up with regular gas at intervals.

Regardless of what route you take, it is imperative to ensure that the flex-fuel does not stay in the tank for a long time because of potential engine risks.

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Can you mix regular and flex-fuel?

Yes, you can mix flex-fuel and regular gas. However, you cannot use the mix in all cars. Only cars supporting high ethanol blends operation are suitable for this mix.

If your car does not support the use of flex-fuel, you might have issues with your engine if you use the mix. Frequent engine knocks might occur as Ethanol packs more torque and horsepower than regular gas, putting too much strain on the engine.

Most flex-fuel cars are designed to adjust to different blends of Ethanol and gas; hence, your engine might not notice the difference if you mix both fuels. Meanwhile, it’d be essential to confirm with the manufacturer if your engine is adaptable to the difference in composition of various blends.

Does using regular gas in flex-fuel harm the motors?

No, regular gas use in flex-fuel cars does not harm the motors. Any vehicle operating on gasoline will function just fine with regular gas without any issue. However, you might want to avoid the leaded version of regular gas as it is not safe for your engine. Obtaining leaded gas at your local filling station is highly unlikely, but it wouldn’t hurt to confirm before filling up your tank.

What kind of gas can I put in a flex-fuel vehicle?

Flex-fuel vehicles can operate on regular gas and gas blends with varying proportions of Ethanol, including flex-fuel with high ethanol content. All gasoline cars can run on regular gas without any issue. The cars might not be able to reach their maximum performance but will work fine.

Therefore, if you drive a flex-fuel vehicle and do not have access to flex-fuel at any point, you can fill up with regular gas till you get your preferred fuel.

Although regular leaded gas is not standard these days, if you come across it, it is not suitable for your car. It could lead to some severe issues with your engine. If you intend to use regular gas in your flex-fuel vehicle, ensure it is the unleaded variant.

While regular gas is suitable for your engine, your safe bet in ensuring better performance and a cleaner engine is using E85 (flex-fuel). Ethanol in the gas is a good cleaning agent, which might even help you save up on the cost of injector cleaners.

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Which cars use flex-fuel?

Only vehicles designated as flex-fuel compatible by the manufacturers can use flex-fuel. Otherwise, stick to other gas variations suitable to your engine

There are flex-fuel vehicles in different automaker brands, and you can easily confirm if your car is flex-fuel friendly. The gas cap is often yellow; you might even have it printed on the fuel cap.

Flex-fuel cars are the only vehicles capable of using flex-fuel, maximizing their higher performance and cleaner drive without facing any cases of engine roughing.

Here are the main advantages of flex-fuel over gasoline

Why would you choose a flex-fuel vehicle over a conventional one? Here are some of the benefits to keep in mind:

Cleaner emissions

Flex-fuel cars have proven to be more environmentally friendly than traditional gasoline. These vehicles burn cleaner, meaning less toxic fumes into our environment.

Versatility

Flex-fuel vehicles are great for people who want the flexibility to burn any proportion of fuel mixture it has in its combustion chamber at any given time.

Sustainability

The majority of flex-fuel cars run on Ethanol. Ethanol is produced from sustainable resources, such as corn and cane sugar.

Save on taxes

Flex-fuel cars are a great way to save on taxes. The flex tax credits can reduce or even eliminate your liability to pay taxes.

Increased performance

Flex-fuel vehicles don’t experience a loss in performance when using E85 fuel. Some even generate increased torque and horsepower! Bentley announced as soon as 2010 that all its Continental models will have a flex-fuel capability as standard.

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Here are the main disadvantages of flex-fuel over gasoline

What should one keep in mind when looking to buy a flex-fuel vehicle? Here are some of the drawbacks:

Poor MPG

This is one of the most significant disadvantages of using flex-fuel over gasoline. While some drivers reported similar MPG, most car owners noticed a drop in their MPG. Flex-fuel has a “gasoline¬†gallon equivalency” (GGE) value of¬†1.52, meaning that you will burn 1.5 gallons of Ethanol to obtain the same amount of energy from burning 1 gallon of gasoline.

Ethanol fuel stations are hard to come by

Although the number of stations offering E85 has increased lately, the percentage of fuel stations offering flex-fuel is still relatively low. According to AFDC, out of 63,240 fuel stations in the US and Canada, only 4,292 sell Ethanol.

That is not even 10%! You can check here which stations sell E85 in your area.

Possible engine damage

The last thing you want to break in your car is the engine! Unfortunately, flex-fuel can cause premature engine wear on some car models.

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Which Vehicles Use Flex-Fuel?

Here is the list of flex-fuel compatible vehicles in 2022:

VehicleFuel TypeFuel Economy
Chevrolet Express 2500/3500Ethanol (E85)no data
Chevrolet Silverado 2WD 2021Ethanol (E85)12 mpg alternative / 16 mpg conventional
Chevrolet Silverado 2WD 2022Ethanol (E85)12 mpg alternative / 16 mpg conventional
Chevrolet Silverado 4WD – Mud Terrain Tires 2022Ethanol (E85)11 mpg alternative / 15 mpg conventional
Chevrolet Silverado 4WD 2021Ethanol (E85)12 mpg alternative / 16 mpg conventional
Chevrolet Silverado 4WD 2022Ethanol (E85)12 mpg alternative / 15 mpg conventional
Ford Explorer AWD FFV 2021Ethanol (E85)13 mpg alternative / 19 mpg conventional
Ford Explorer AWD FFV 2022Ethanol (E85)13 mpg alternative / 19 mpg conventional
Ford F-150 2WD FFV – With Start/Stop 2022Ethanol (E85)14 mpg alternative / 20 mpg conventional
Ford F-150 2WD FFV – Without Start/Stop 2022Ethanol (E85)14 mpg alternative / 19 mpg conventional
Ford F-150 2WD FFV 2021Ethanol (E85)14 mpg alternative / 20 mpg conventional
Ford F-150 2WD FFV 2021Ethanol (E85)16 mpg alternative / 21 mpg conventional
Ford F-150 2WD FFV 2022Ethanol (E85)16 mpg alternative / 21 mpg conventional
Ford F-150 4WD FFV – With Start/Stop 2022Ethanol (E85)13 mpg alternative / 19 mpg conventional
Ford F-150 4WD FFV – Without Start/Stop 2022Ethanol (E85)14 mpg alternative / 18 mpg conventional
Ford F-150 4WD FFV 2021Ethanol (E85)13 mpg alternative / 19 mpg conventional
Ford F-150 4WD FFV 2021Ethanol (E85)15 mpg alternative / 20 mpg conventional
Ford F-150 4WD FFV 2022Ethanol (E85)15 mpg alternative / 20 mpg conventional
Ford Super Duty F-250 2021Ethanol (E85)
Ford Super Duty F250, F350, F450CNG – Bi-fuel / Ethanol (E85) / CNG – Compressed Natural Gas / Propane / Propane – Bi-fuelno data
Ford Transit 250/350 Cargo VanEthanol (E85)no data
Ford Transit Connect Van FFV 2021Ethanol (E85)19 mpg alternative / 25 mpg conventional
Ford Transit Connect Van FFV 2022Ethanol (E85)19 mpg alternative / 25 mpg conventional
Ford Transit T150 Passenger Van 2WD FFV 2022Ethanol (E85)12 mpg alternative / 17 mpg conventional
Ford Transit T150 Passenger Van 4WD FFV 2022Ethanol (E85)12 mpg alternative / 16 mpg conventional
GMC Savana 2500/3500Ethanol (E85)no data
GMC Sierra 2WD 2021Ethanol (E85)12 mpg alternative / 16 mpg conventional
GMC Sierra 2WD 2022Ethanol (E85)12 mpg alternative / 16 mpg conventional
GMC Sierra 4WD – Mud Terrain Tires 2022Ethanol (E85)12 mpg alternative / 15 mpg conventional
GMC Sierra 4WD 2021Ethanol (E85)12 mpg alternative / 16 mpg conventional
GMC Sierra 4WD 2022Ethanol (E85)12 mpg alternative / 16 mpg conventional
Source: afdc.energy.gov

Conclusion

Flex-fuel cars can use regular gas with little or no impact on their engines, but this is not the same for regular gas cars. Flex-fuel should never be used in them. However, if you notice any slight change in your flex-fuel car after using regular gas, be sure to exhaust the gas as soon as possible.

In this case, it is likely that the gas purchased is either of poor quality or contains strains of lead that are bad for your engine.

Before using flex-fuel in your car, ensure that your vehicle is designated for use by your automaker. Otherwise, avoid the use of the fuel and stick to regular gas.