It’s a simple mistake that can happen to anyone, especially when you’re in a hurry or using a unfamiliar fuel pump. The gas and diesel nozzles may look similar, but the fuels they dispense are fundamentally different. Understanding what happens if you put diesel in a gas car is crucial because the consequences are far more severe than simply putting the wrong grade of gasoline in your tank.
What Happens If You Put Diesel in a Gas Car
The moment diesel enters a gasoline engine, the problems begin. Gasoline engines are designed with spark plugs to ignite a highly volatile fuel. Diesel fuel is much thicker and oilier, and it’s not easily vaporized. Instead of igniting from a spark, diesel is designed to combust under intense pressure. In your gas car, the diesel will likely not ignite at all. You might be able to drive for a short distance, but you’ll quickly notice heavy smoke from the exhaust, a loss of power, and severe engine knocking before the car stalls and refuses to start again.
Why This Mixture Is So Damaging
The real damage occurs because diesel fuel will clog the intricate fuel injectors and fuel lines designed for much thinner gasoline. It can also contaminate the entire fuel system, including the fuel pump and filter. Since diesel acts as a solvent, it can damage the seals and rubber components in your fuel system. If the diesel reaches the combustion chambers, it can’t be properly burned and may wash away the protective oil on the cylinder walls, leading to potential scoring and severe internal engine damage.
The Critical Steps to Take Immediately
If you realize the mistake before starting the car, consider yourself very lucky. Do not turn on the ignition. Doing so primes the fuel system, drawing diesel into the engine. In this scenario, the fix is much simpler and less expensive. You will need to have the car towed to a mechanic who can completely drain and flush the fuel tank. If you did start the car and drive it, the repair process becomes more complex. The mechanic will need to drain the tank, flush the entire fuel system, and potentially replace the fuel filter, injectors, and pump.
While it’s a stressful and costly error, putting diesel in a gas car is a mistake that can be rectified. The key is to act quickly and not operate the vehicle. By getting a professional to clean the system thoroughly, you can often avoid catastrophic engine damage and get back on the road.