What Happens If You Fill Your Car With Diesel?

The fuel pump will struggle to transfer the diesel/gasoline mixture through the system since diesel fuel is thicker and denser than gasoline. Additionally, the diesel will be unable to pass through the fuel filter easily. It will instead clog the fuel filter. And any diesel that makes its way into the engine will block the fuel injectors, rendering them useless. The engine will clog up and seize as a result of this. The gasoline engine may continue to run after the diesel tank has been filled, but this is only because it is still running on the residual gasoline in the fuel line.

Even if the circumstance is unpleasant, the alternative — putting gasoline into a diesel tank – is even worse. Because of its enormous combustion potential, gasoline would ignite more faster than diesel fuel. The diesel engine and its components could suffer catastrophic damage as a result of the early ignition and volatility.

What happens if you accidentally fill your car with diesel?

You’ll require an emergency tow to the mechanic, who will be able to drain the diesel fuel from your tank and clean it with regular gasoline to remove any diesel residue. After the mechanic removes the diesel fuel from the tank, he or she will refuel the engine with standard gasoline and start it.

Will diesel ruin a gas engine?

Will a gas engine be ruined by diesel? If diesel is detected early enough, it is less likely to cause serious engine damage. The mixture of gasoline and diesel will not burn efficiently, resulting in spark plug damage, engine misfires, and damage to the catalytic converter. It will finally come to a halt.

How much diesel does it take to ruin a gas engine?

Let’s imagine you mix a small amount of gasoline with your diesel fuel by mistake. The first thing it’ll do is lower the flash point of the diesel, which can be harmful because pockets of greater gasoline concentrations can form in a tank. As a result, the flash point would be inconsistent across the tank.

Given the wide difference in flash point temperature between gasoline and diesel, it only takes a small amount of gasoline to drastically lower the flash temperature. Even a 1% gasoline contamination lowers the diesel flash point by 18 degrees Celsius. This indicates that the diesel fuel will ignite early in the diesel engine, perhaps causing harm to the engine.

Contamination with gasoline can harm the fuel pump and cause diesel injectors to malfunction.

This occurs due to a lack of lubrication. To put it another way, gasoline is a solvent, but diesel is an oil. Diesel has enough lubricity to keep the fuel pumps and injectors lubricated. By replacing the oil with gasoline, the lubrication is lost, resulting in damage.

Beyond them, you’ll get incomplete combustion, which produces a lot of black smoke at first. Beyond being a cosmetic issue, the vehicle’s computer will modify the fuel-air combination to compensate for the absence of combustion. This will significantly reduce your power and performance. Furthermore, if you continue to use the fuel, you risk overheating or covering the vehicle’s computer sensors in soot that they become unable to detect anything.

Putting Diesel into Gasoline

Now consider the opposite situation: you’re mixing a higher flash, heavier fuel with a lighter, more volatile base fuel (gasoline) that burns at a much lower flash temperature. Some may believe that this “diesel-in-gasoline” scenario is less dangerous than the opposite. However, this is not the case.

The loss of octane is a major concern when gasoline is contaminated with diesel fuel. When considering how gasoline burns in an engine, the octane rating is a gauge of the fuel’s ability to ignite at the proper moment – not too soon. Once pumped into the chamber, gasoline with a lower octane rating will ignite too rapidly. The gasoline ignites and explodes, but the piston is still rising, and the subsequent pressure wave collision causes a knocking sound (at best) and damage to the piston and rod (at worst). Octane, in a way, slows down and delays combustion.

To match today’s car engines, gasoline must have an octane rating of 87-91. The octane rating of diesel fuel is 25-40. By mixing 2% diesel fuel with gasoline, the overall octane rating is reduced by one point. The octane of diesel that has been contaminated by 10% drops by 5 points, which is enough to cause issues in most engines. With increasing percentages of diesel fuel in gasoline, the octane depression rises linearly.

  • Because diesel fuel is heavier than gasoline, it might settle to the bottom of your gas tank, causing both gas and diesel to be injected into the intake manifold or cylinder. Partially-burned diesel fuel, depending on the mix, can leave large deposits on pistons, valves, and spark plugs. You buy a car or truck that runs poorly, and if you continue to drive it, you risk catastrophic harm.
  • If enough diesel fuel gets into the cylinders, the cylinders can hydro-lock, resulting in a blown head gasket, broken cylinder head, or other catastrophic issues that can lead to your vehicle’s premature death.
  • This diesel fuel can seep through the piston rings and into the oil crankcase, diluting the lubricating oil. This can cause damage to all lubricated internal engine elements, resulting in significant engine failure due to accelerated wear.
  • Unburned diesel fuel will ignite in the catalytic converter if it enters the exhaust system unburned. The fire will fill the holes in the catalyst, ruining it and costing you thousands of dollars to replace.

The Bottom Line – Don’t Drive It

Because it’s hard to tell how much of the improper kind of fuel is in your tank and fuel system, the best advice is to have your car towed to a mechanic’s garage where the problem may be fixed.

They will remove all of the fuel from the filter and flush the system to remove the issue fuel once they arrive at the garage.

Some could say, “Well, my (fill in the blank with a friend, coworker, relative, or general practitioner) got some in his tank by accident, and he drove it and it was OK.”

There’s no way to determine how your circumstance compares to theirs in certain instances (and human nature dictates that we downplay our descriptions of prospective difficulties if they arise from a mistake we’re responsible for).

You have been told not to drive the car if you believe the improper gasoline has been dispensed. In any event, we advise you to avoid taking that risk.

Will a small amount of diesel damage a petrol engine?

The industry typically views 5% or less of diesel in gasoline as a safe amount. If the engine starts, it will be strained because the diesel in a hot engine will combust too quickly, causing the engine to operate hotter than it was designed, perhaps damaging the pistons and other components.

Can you accidentally put diesel in a petrol car?

Because the diesel pump nozzle is larger than most petrol filler necks, it will not fit. As a result, putting the wrong fuel in a petrol car is significantly less common than putting petrol in a diesel engine.

Plus, putting diesel in a petrol engine isn’t as dangerous as it is for a diesel engine, so there’s normally less damage.

It’s a huge annoyance. However, it isn’t as serious as the harm that gasoline may do to a diesel engine. Once the fuel has been emptied away, your petrol engine should not be permanently damaged.

Can you put diesel in a plastic gas can?

Polyethylene is a typical synthetic material used in the manufacture of plastic storage drums, such as the famous blue plastic barrel found in warehouses all over the world.

While plastic drums can be used for a variety of things, from storing food to transporting hazardous waste, businesses frequently question ITP’s staff if they’re safe to use for storing diesel fuel.

Yes, polyethylene plastic (especially a specific plastic oil drum) is safe for storing diesel fuel, although there are some limitations to how long it may be securely stored. Our team shows how polyethylene plastic may be used to safely store diesel in this post, as well as what you should be aware of while using it for fuel storage.

Are diesel nozzles bigger than gas?

Because diesel nozzles are larger than gasoline nozzles, they will not fit in your gasoline vehicle’s tank. The tiny gasoline nozzle will readily fit into diesel filler necks, thus diesel drivers should exercise particular caution.