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Using gasoline fuel into a diesel engine or vice versa, who’s crazy enough to do so - you might ask! But believe it or not, more than 150,000 people tend to pour the wrong fuel into their cars each year, either by choosing the wrong fuel nozzle, or simply being unfamiliar with the recommended fuel type for their vehicle.

It might seem like a simple harmless conflict for some, but its effects can break the bank!

In this article, we will explain the difference between gasoline fuel and diesel fuel, explain the potential harm, and go through your alternatives so you'll know what to do next.

Gasoline Fuel & Diesel Fuel: Are They Different?

although all fuel grades serve the same main goal, each grade would function differently


To understand why the type of fuel we use in our vehicles matter, you must first learn the distinctions between gasoline and diesel fuel. These two fuels have the same goal in igniting your vehicle, but the methods are different.

Gasoline & diesel differ in three ways; their features, their produced power, and their functionality in the engine.

  • Fuel Features:

While both gasoline and diesel are extracted from the ground as crude oil, the refining process divides them into distinct forms of fuel. Diesel is made by using a hydrocarbon mixture that is a byproduct of the distillation of that crude oil, which in return results in a denser fuel that has a slower evaporation rate. On the other hand, gas fuel has a thinner formula which makes it evaporate very quickly at room temperature.

Diesel fuel is classified as a combustible liquid that requires compression and heat to ignite and function. While gasoline is considered as a flammable liquid that requires a spark to ignite and function. So if you bring a match and toss one in a tank filled with diesel and the other in gas, you will notice that nothing’s going to happen to the one filled with diesel, as a fire will start in the one filled with gas. Please be safe and don’t attempt to try!


  • The Produced Power:

For a fact, there are plenty of reasons why diesel is considered to be more powerful than gas. Here are some quick points to know more about the produced powers of both diesel and gasoline fuels.

  • The power generated from diesel combustion is many times greater than the one generated from gas. In other words, Diesel fuel becomes more efficient as the power output rises.
  • Diesel has a higher energy density than gasoline.
  • Ethanol, an additive that increases efficiency, is not needed in diesel fuel.
  • Diesel fuel is extremely efficient for trucks and heavy machinery uses, and less effective for daily use and sports cars.
  • Diesel operates less effectively in cold weather than normal gas. It is known, however, that it performs better at higher elevations & altitudes.


  • Fuel Functionality within Engines:

The most significant difference between the two fuels is how they function within an engine.

Direct fuel injection is used in a diesel engine, which means the fuel is injected directly into the cylinder. It's built to endure a lot of pressure and heat. This engine may also include a glow plug, which improves the efficiency of the combustion process in cold temperatures.

In contrast, gasoline engines require less pressure and heat since the spark plug produces enough spark to ignite the fuel.

So What Happens If I Used the Wrong Fuel in My Engine?

did you know that using a small amount of gasoline fuel in a diesel engine can lead to serious damages

As long as you realize your error at the fuel pump, mixing gasoline and diesel fuel isn't the end of the world. Yes, you'll have to go through the hassle and expense of having your fuel tank pumped & fixed, but the real damage might happen after you have driven away. Let’s see what will happen in both scenarios:


  • I’ve Used Gasoline Fuel into My Diesel Engine:

Using gasoline in a diesel tank does more serious damage than the other way around. Even a small amount is capable of doing extreme harm to your vehicle that may lead into unrepairable engine damages!

Most gasoline fuel nozzles are much thinner than diesel fuel nozzles which easily can fit into the filler neck of a diesel car's fuel tank. With such, it is very common among drivers to misfuel.

Diesel engines are harmed by gasoline for the following reasons:

  • Diesel functions as a lubricant, allowing the fuel pump to operate more efficiently.
  • Gasoline, on the other hand, does the opposite function. It will cause more friction between the components in a diesel engine.
  • As a result of this friction, your diesel engine will severely suffer.
  • The more gasoline is added into your diesel engine, the more damage it will do.
  • That is why it is critical and super important not to start your vehicle.

Remember, that today’s Clean Diesel and Common Rail diesel cars have become significantly more sensitive to gasoline than their predecessors. A small damage could lead into a new fuel pump, injectors, pipes, or even an entirely new engine.


  • I’ve Used Diesel Fuel into My Gas Engine:

Using diesel into gasoline vehicles is not as easy as pouring gasoline into diesel cars. Why? Since diesel pump nozzles are larger than most gasoline filler necks, it will not fit. As a result, using the wrong fuel in gasoline cars is considerably less common than pouring gas in diesel cars.

However, using diesel in a gasoline engine isn't as harmful as it is for a diesel engine, so there's usually less damage.

When you use diesel in a gasoline engine, here's what will happen:

  • Gas fuel is ignited by a spark from the spark plugs.
  • And since the diesel fuel is heavier, it will clog the spark plugs and the fuel system of the gasoline engine.
  • Which implies that simply the vehicle will not start!

It's very annoying. But it's nothing compared to the harm & damage gasoline can do to a diesel engine. Once the fuel has been drained completely, your gasoline engine should be safe.

OK Tell Me, What Should I Do in a Situation Like This?

remember not to start your car if it has been filled with the wrong fuel


Did you start your car yet? If not then don’t!

The most serious damage usually happens if you turn on your engine after misfueling.

You’re in luck if you realized your misfueling before starting your engine. And here is how you should proceed:

  1. Avoid putting your key in the ignition and keep your engine switched off.
  2. Place your car in neutral.
  3. Push your car over to a safe place.
  4. Call for the nearest mechanic to help drain and flush your fuel system.

And if not and you’ve already started your engine, don’t panic and do the following:

  1. If it's safe to do so, turn off the engine right away. If this is not the case, pull over to a safe location.
  2. Place your car in neutral.
  3. Call for the nearest mechanic to help drain and flush your fuel system.

Is There Anything I Can Do to Avoid a Misfueling Situation?

بإضافة ملصق درجة الوقود على خزان الوقود الخاص بك سيساعدك من استخدام الوقود الخاطئ

When you're driving a new car or even many different cars, it's easy to become confused at the gas station. Here are some helpful tips to avoid the hassle of using the wrong fuel:

  1. Before filling up, search for additional signs rather than relying on the color of the fuel nozzle.
  2. Read the pump's trigger label and the fuel grade indicator correctly.
  3. Install reminders in your vehicle, such as a sticker inside the gasoline cap.
  4. Distractions aren't worth it, so put your phone down and focus entirely on the pumps.
  5. If you're in a rush, hungry, or anxious, you're more likely to make a mistake.
  6. Do you own a diesel? Purchase a stopper for the filler neck to prevent the smaller gas nozzle from fitting.