Petrol and Diesel: What Happens If You Use the Wrong Fuel in Your Car?

Cars around the world, in their various types, still operate on fuel combustion, as electric cars are making their way to the streets. The use of diesel fuel in cars is as common as gasoline, raising the perennial question among car owners: Can diesel fuel be used in a gasoline engine, and vice versa?

Using the Wrong Fuel in Your Car

In this article, we will answer this frequently asked question on various platforms. We will discuss the distinctive features of gasoline and diesel fuels separately and then explain what can happen if gasoline is used instead of diesel and vice versa.

Difference Between Gasoline and Diesel Fuel

Internal combustion engines generally operate similarly in their working and rotation. However, there are differences, such as the type of fuel used. Diesel engines are built in a specific way, as are gasoline engines. This is due to the nature of these substances in terms of density, combustion speed, resulting power, and how they rotate in the engine.


  • Requires high pressure and temperature for combustion.
  • Produces more energy and power than gasoline.
  • Used in trucks and heavy vehicles.
  • Works more efficiently in hot atmospheres compared to cold ones.
  • Diesel engines include a component called a glow plug, which supports the combustion process due to the difficulty of igniting diesel and its need for high temperatures.
  • Injected directly into the cylinder.


  • Highly flammable.
  • Does not require high pressure and temperature for combustion; it needs a simple spark generated by spark plugs.
  • Suitable for daily use in cars.
  • Produces less energy and power.
  • Injected into the cylinder by injectors in specific ratios.
  • Higher fuel consumption.

What Happens When Gasoline is Used Instead of Diesel?

As mentioned above, the density of diesel fuel is higher than that of gasoline, a characteristic needed by the fuel pump in a diesel engine for efficient operation. If gasoline, with its lower density, enters the fuel pump and other engine parts, the engine’s operation will be disrupted, leading to friction and wear over time if the owner continues to use gasoline. This usage will result in multiple and costly damages, even if the proportion of gasoline used is small. The more gasoline is used, the more the damage increases. Therefore, if your diesel engine car is fueled with gasoline, it is strongly advised not to start it and not attempt to drive it at all.

What Happens When Diesel is Used Instead of Gasoline?

Using diesel in a gasoline engine is less common and, in general, not a practice for many due to the small fuel inlet nozzle in gasoline stations that cannot accommodate a diesel pump. If, for any reason, a car owner fills diesel instead of gasoline, the spark plugs will not be able to generate a spark due to the density of diesel. The car will struggle with reduced engine power after a short distance, and the driver will notice engine hesitation. After a short period, the engine will stop running, and black smoke may be observed coming from the exhaust.

Advice from MotorCoaster

Ensure that you are fully aware and conscious when refueling your car, and do not perform this operation while distracted. If you accidentally use the wrong fuel, never start the car and seek assistance from a maintenance center to drain the fuel and clean the engine components.

As always, we remind you to visit maintenance centers for regular and comprehensive car check-ups to ensure its safety from time to time.

Finally, you can read the latest car news. You can browse the car reviews section on Motorcoaster to learn about the latest developments in the exciting automotive world, and you can view the best car tips & advice for maintaining your car to make it last longer.

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