Can You Put Regular Gas in E85 Vehicles?

There are affiliate links on this article. If you make a purchase through any of the links, I may earn a small commission at no extra cost to you.

Is it cool to put regular gas in a vehicle designed to use flex fuel? FFVs – Flex Fuel Vehicles – have a specially designed engine that can run with multiple fuel varieties. However, the most common, and recommended fuel to put in FFVs is “E85,” which signifies a fuel with 85% ethanol and 15% gasoline.

But can you put regular gas in E85 vehicles? Yes, it’s cool to fill regular gas (87 gas) into the gas tank of your Flex-Fuel Vehicle.

But of course, there are rules for these things; if you’re going to use a different fuel instead of the recommended fuel by your FFV manufacturer, then you should know more about using regular gas in flex-fuel cars.

Can You Put Regular Gas in E85 Vehicles?

E85 vehicles are simply flex-fuel vehicles, which are vehicles designed to use a variety of fuel blends. However, they are called E85 vehicles because they mainly run with E85 gas. E85 gas is a fuel with 85% Ethanol content and 15% regular gasoline, or any other hydrocarbon (depending on the need).

So, literally, an E85 vehicle cans run with (only) regular gasoline because the engine supports that too. It’s understandable to be skeptical about running a different fuel on your vehicle, but it’s all about what the engine can take. Flex Fuel Vehicles have an engine that can run with different types, and blends of fuels.

It is completely safe to put in 87 or 91 gas to your flex-fuel vehicle. The internal combustion engine of FFVs automatically adjusts to the ratio of ethanol present in the fuel in the gas tank and then runs with it.

How E85 Vehicles Work When You Put In Regular Gas

Apparently, every vehicle runs with the information provided by the ECU, which acts as the central computer. The ECU receives information from all components of the vehicle, including the fuel lines and combustion chamber.

So, when you add an 87 or 91, the ECU detects low ethanol, thanks to the fuel system sensors, and adjusts the combustion process. To adjust the combustion process, the ECU simply needs to adjust the air-to-fuel ratio and other engine parameters so that the engine would keep running optimally.

With the adjustments, the ECU makes your FFV run like a regular gasoline car. In the same way, when you refill E85, the ECU re-adjusts the air-fuel ratio and other engine parameters too, so the car runs as designed by the manufacturer.

The main point is that FFV engines can run smoothly with any ratio of ethanol to gasoline; even if the fuel you topped doesn’t have ethanol at all, the engine would still run. More so, even regular gas has ethanol inside – though a very small percentage – around 10%.

Ethanol is more like a fuel additive gotten from corn; it helps to reduce emissions and improve fuel economy. People seem to prefer cars that run with E85 gas due to the high ethanol concentration, which means improved eco-friendliness. E85 is renewable gas.

See Also: Difference Between E85 and Regular Gas


So, can you put regular gas in E85 vehicles? The short answer is YES. E85 vehicles can run with only ethanol-based fuel, regular gas, or a blend of both ethanol and gasoline. The ECU is what does the calculation to adjust the air-fuel ratio depending on the type of fuel you put into the car.

Well, E85 is typically more expensive and not too easy to find; in some regions, you’d hardly find a fuel station that sells E85 gas, which is why a lot of drivers seek to know if regular gas would be cool in a flex-fuel vehicle.

Scroll to Top