There are safeguards in place to ensure that you pump the right fuel, but in case one accidentally uses the wrong pump, knowing the right response can make a difference when it comes to fixing the mistake.
For petrol engines, there are usually different qualities available, identifiable by the RON (Research Octane Number). Here, the “wrong” fuel has less potential of causing harm. We want to spend a moment on discussing this for the completeness of this post. If one uses a fuel with a higher RON number than required, there won’t be any harm. The higher Octane number indicates that the fuel is less prone to pre-mature combustion and oftentimes has a more sophisticated mix of additives. Upwards is not a problem; one may however end up spending more money on fuel although not needed. If the fuel used is of a lower Octane number, the pre-mature combustion will manifest itself in a ringing noise and loss of power. Over time, there could be damage to the engine as the engine is not combusting the fuel correctly.
Mixing Diesel and Petrol however is a serious concern. To prevent this, the nozzles have different diameters, preventing the Diesel nozzle to be inserted into the filling stud of a petrol car. It can still happen though that one pumps the wrong fuel. Immediate action is required to prevent costly damages to the fuel pump and engine.
German Motors recommends the following courses of action. If the car hasn’t been started upon realisation that the wrong fuel was inserted, do not start the car. Push it away from the pump and into a safe spot. Call a tow truck and have the vehicle moved to a trusted workshop. German Motors would carefully remove the tank and drain it. Following the removal of the fuel, the tank will be flushed to remove any residual fuels, ensuring that the contamination is completely removed. A precautionary flushing of the fuel system will be recommended.
Should the vehicle have been driven for a while before realising the mistake, the procedure is to immediately stop the car in a safe space. Then have it towed and undergoing the same procedure as above with the difference that the engine has to be flushed and checked for damage.
It is imperative to not try mixing the wrong fuel with the correct fuel by adding more of the right fuel to the tank. Also, the car should not, under any circumstances, be driven to a workshop.
