What is a possible consequence of over-filling the engine with oil?

Over-filling the engine with oil can lead to damage to the catalytic converter because excess oil may cause the engine to produce more vapor and smoke when the oil is pushed past the piston rings. This can lead to oil entering the exhaust system, where it can burn and generate harmful emissions. As the catalytic converter attempts to process these extra pollutants, it can become overwhelmed and subsequently damaged, impairing its ability to convert harmful exhaust emissions into less toxic substances.

The other options suggest beneficial outcomes, which do not occur as a consequence of over-filling. In reality, over-filling can negatively impact engine performance and efficiency, and it does not contribute to an extended engine life; rather, it poses risks to various engine components, including the catalytic converter.