What Happens if You Put Diesel in a Gas Car?

March 10th, 2021 by

You pull up to the gas pump the same as any other day, but today, you didn’t pay attention to the type of fuel dispensed by the pump. You suddenly realize you’re pumping diesel into the tank of your gasoline-powered car, and you’ve already put in a couple of gallons. You can’t leave your car sitting at the gas station until you resolve the issue, so what happens next? The following is a look at what happens when you put diesel in a gas engine and how to handle the problem.

gas vs diesel engine

What You Should Do if You Put Diesel Into Your Gas Tank

Don’t panic. And above all else, don’t start your car, which will cause the engine to turn over. You don’t want the fuel pump to draw the diesel fuel into your engine, as it will clog up your fuel system and potentially damage the moving parts in your engine block. It’s also a bad idea to leave the diesel in the tank for any length of time. You’ll need to get an emergency tow to the mechanic, where trained technicians can pump the diesel fuel out of your tank, then rinse it with regular gasoline to remove any diesel residue.

After the mechanic clears the diesel fuel from the tank, he or she will put regular gasoline back in and start the engine. If you avoided turning your car over after pumping diesel, the vehicle should start and operate as normal. You might notice black smoke coming from the exhaust as the car burns off diesel that’s been left behind, but that smoke will disappear eventually. As long as you took precautions to not start the engine after putting diesel fuel in your tank, your car will be fine and won’t suffer lasting damage.

chevy corvette engine red

The Difference Between Diesel and Gasoline Engines

Gasoline engines are also known as internal combustion engines (ICE) because they burn fuel when it passes into the engine. Spark plugs ignite the gasoline, and the resulting combustion causes the cylinders to push downward into the engine block. The action of the cylinder pushing down also turns the crankshaft and makes another cylinder move further downward or upward. Provided the engine works as it should, the action causes the engine to run and propel the car forward. A diesel engine works in the same fashion, except it compresses fuel instead of burning it.

Diesel engines, also known as compression ignition engines (CIE), use glow plugs instead of spark plugs. This is the only major difference between a gasoline engine and a diesel engine. The diesel engine uses what’s known as compression ignition of air and fuel to make the cylinders turn. Air gets drawn into the cylinder chamber and compressed by the piston, then the fuel injector injects fuel into the hot air, which causes the fuel to ignite from the intense heat and the cylinder to move down.

It’s important to understand the differences between the two types of fuel ignition if you ever have to deal with accidentally putting diesel into a gasoline car. The more you know about how your engine operates, the faster and better you can react to and resolve an engine fuel mix-up.

Why Gasoline Is Different From Diesel Fuel

The biggest difference between gasoline and diesel is their density. Diesel fuel is more viscous, or thicker, than gasoline. Gasoline is thin and has an odor like paint thinner, while diesel smells more like strong kerosene. A quick sniff or slosh of the container can tell you what type of fuel it has. The major reason diesel differs from gasoline comes down to how the engine consumes the fuel to operate.

Gasoline is classified as a flammable, whereas diesel is a combustible. With an ICE, fuel gets injected into the cylinder chamber via the opening of a valve. The spark plug causes the fuel to ignite and power the engine block. Diesel fuel gets injected directly into the cylinder chamber, where it’s compressed instead of ignited. The result is the same: The cylinder gets pushed downward, and the engine runs as expected.

Both types of engines are incompatible with each other’s fuel. That is, you can’t run a diesel engine on gasoline, and you can’t run a gasoline engine on diesel. Diesel is too thick for a gasoline’s fuel pump system, and gasoline creates too large of an explosion for a diesel engine to handle.

Tips To Avoid Pumping Diesel Into Your Car

The main visual cue that says “this is a diesel pump” is the color of the handle. Diesel pump handles are typically green, while gasoline pump handles are black and might have octane rating cards attached to the top. The nozzle of a diesel fuel pump is larger in diameter than the opening on a gasoline tank. You won’t be able to insert the nozzle of a diesel pump into the fuel neck of your gasoline car, no matter how much you try. Diesel also smells different and has a consistency akin to a light oil.

Gasoline and diesel distributor at the gas station. Gas pump nozzles. Petrol filling gun close-up at the gas station. Colorful Petrol pump filling nozzles. Fuel pump

Gas stations are careful to place all these cues to inform you that you’ve picked up a diesel pump, so you can put it back before pumping the wrong fuel into the tank of your gasoline car. If you keep a can of diesel in your garage, make sure the container has a different color, label, and storage space than cans of regular gasoline. Careful storage helps you eliminate the risk of putting diesel fuel into your gasoline-powered car.

Sweeney Chevrolet Has the Right Car With the Right Engine for You

Come see us at Sweeney Chevrolet for your next vehicle. We carry Chevrolet models with four-cylinder engines that offer economy and reliability for daily commutes, as well as heavy duty pickup trucks with Duramax diesel engines capable of hauling just about anything you need to tow or transport.

Check out what we have on our lot, and drive home today in a new Chevrolet.

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