Diesel Into Petrol
Putting diesel into petrol engine is a serious misfuelling error, though generally less destructive than the reverse, provided the engine is not run for long.
Diesel is thicker and oilier than petrol, and when introduced into the petrol system, it immediately contaminates the lighter fuel. If the engine is started, the diesel will quickly coat and clog the spark plugs, injectors, and fuel lines, preventing the spark plugs from igniting the fuel mixture effectively.
Putting diesel into a petrol engine is a surprisingly common mistake, but it requires immediate action to prevent long-term damage.
The most critical rule is do not start the engine or even put the key in the ignition, as this can prime the fuel pump and circulate the diesel further into the system.
While putting diesel in a petrol car is generally less catastrophic than the reverse, you will still need a professional fuel drain to flush the tank and ensure your engine remains healthy and functional.