Posted on 10/30/2026

Put the wrong fuel in your tank? Leave the engine off. That one decision gives you the best chance of keeping the repair manageable. Starting the car to move away from the pump sends contaminated fuel toward components that depend on the right fuel to work properly. It happens surprisingly easily when you're driving a rental, borrowing a truck, or switching between gas and diesel vehicles. The damage depends on what went into the tank, how much you added, and whether you drove afterward. A car that stayed at the pump needs different repairs than one that stalled several miles down the road. How Wrong Fuel Reaches the Fuel System The tank is only the beginning of the fuel's journey. Pumps push it through filters and lines toward the injectors, which deliver carefully controlled amounts to the engine. Once the wrong fuel travels through that system, removing it becomes more involved than emptying the tank. If you caught the mistake before starting ... read more