What Happens If You Put the Wrong Fuel in Your Car?
3 Answers
Hazards of using the wrong fuel in a car: 1. Using a lower octane fuel than required: The car may experience insufficient power and higher fuel consumption, but as long as it's not used long-term, it won't cause significant damage. Conversely, using a higher octane fuel than required generally has no adverse effects. 2. Adding gasoline to a diesel vehicle: The car may start, but due to incomplete combustion of gasoline, it will gradually lose power while driving, leading to shaking and white smoke. In such cases, the fuel system must be thoroughly cleaned. 3. Adding diesel to a gasoline vehicle: The vehicle won't start. Diesel has a lower ignition point, and while gasoline ignites via spark, diesel ignites under compression. The spark plugs may cause diesel to ignite prematurely, leading to knocking, engine damage, black smoke, vehicle shaking, and failure to start. In severe cases, the engine may be damaged. In such situations, contact a repair shop to clean the fuel system.
I once accidentally put diesel into a gasoline car. Fortunately, I didn’t start the engine—ignition would have made the consequences even worse. When the wrong fuel enters the engine, gasoline cars require fuel with a high combustion point, while diesel is harder to ignite and can clog fuel injectors, damage pistons, and ruin the lubrication system. A friend of mine had to tow his car straight to the repair shop, spending thousands to clean the fuel tank and replace parts. If this happens, don’t hesitate—tow it immediately. Always check the label on the fuel cap before refueling, especially since diesel nozzles are larger and easier to mistakenly insert. It’s recommended to add a visible marker to distinguish them. Develop good refueling habits, like avoiding it when tired to reduce mistakes. Knowing your car’s fuel type can also prevent risks—don’t underestimate this, as it saves a lot on maintenance costs.
As someone who frequently tinkers with cars, I think misfueling is quite common, especially mixing up octane ratings. For example, if a car that requires high-octane fuel is filled with low-octane gasoline, it will cause knocking sounds during startup, the car will shake and feel sluggish, and it won't be able to pick up speed. Long-term use can also damage internal engine components and affect performance. I've made that mistake before, but luckily I added some additives to neutralize it, and just upgraded the fuel grade next time. But what's worse is putting gasoline in a diesel car—gasoline burns too quickly, causing overheating and engine seizure. Don't start the engine; just call someone to drain the fuel. Remember to check the fuel pump label and the car's manual, and make it a habit to only use the specified fuel. Don't switch fuels randomly just to save money.
