What could a worn spark plug in a vehicle's engine potentially cause?

A worn spark plug can lead to an engine misfire because its primary function is to ignite the air-fuel mixture in the combustion chamber. When a spark plug becomes worn, it may not generate a strong enough spark to ignite the mixture effectively, leading to incomplete combustion. This can result in misfires, where the engine skips combustion in one or more cylinders. Misfiring can cause a variety of performance issues, including rough running, reduced power, and increased emissions. Ensuring that spark plugs are in good condition is crucial for smooth engine operation.

While other options may also be associated with spark plug issues to some extent, misfiring is the most direct and clear consequence of a worn spark plug. Engine overheating, increased fuel consumption, and rough idle can have multiple causes, while a misfire is a specific outcome of spark plug degradation.