What to Do If You Accidentally Add One Liter of Diesel to a Gasoline Car?

[AlexLynn]

Here are the steps to handle the situation of mistakenly adding diesel to a gasoline car: 1. After realizing the wrong fuel has been added, do not attempt to start the engine to prevent diesel from entering the fuel system. Then, tow the car to a 4S shop or repair shop to drain the diesel completely and refill with gasoline. If the amount of diesel added does not exceed 5-10% of the tank's capacity and is detected promptly, there should be no major issues—simply refill with gasoline, and it won’t cause any significant impact. 2. In reality, most drivers who add the wrong fuel don’t notice it immediately. Instead, they realize it only after driving for a while when the car shows abnormal symptoms such as severe vibration, poor acceleration, or even stalling. In such cases, call for roadside assistance immediately. At the repair shop, besides draining the diesel, the fuel system needs to be cleaned, the gasoline filter replaced, and a comprehensive inspection performed. In most cases, the engine will stall before severe knocking can cause catastrophic damage, so situations like the one shown in the image below are generally rare. Here’s why diesel should not be added to a gasoline engine: 1. Diesel has a lower auto-ignition point, so diesel engines use compression ignition. They don’t require spark plugs; instead, they compress air to raise the temperature to the diesel’s ignition point, then inject diesel, which ignites spontaneously. 2. Diesel engines don’t have spark plugs. If diesel enters a gasoline engine, it starts burning violently before the spark plugs ignite, causing abnormal pressure in the combustion chamber—commonly known as knocking. 3. Additionally, the fuel injector pressure in gasoline engines is much lower than in diesel engines. When diesel is added to a gasoline engine, it cannot be fully atomized, leading to incomplete combustion. This results in a lack of engine power, unresponsive acceleration, severe carbon buildup, and clogged fuel injectors.