What is a sign of spark plug wear?

A cracked or corroded plug insulator is a clear indication of spark plug wear. The insulator is the ceramic part of the spark plug that helps to protect the internal components from the high voltage needed to create a spark. Over time, exposure to high temperatures and combustion gases can lead to physical damage, such as cracking, or chemical corrosion.

When the insulator is compromised, it can lead to misfiring, reduced engine performance, or increased emissions. Monitoring the condition of the spark plug insulator is crucial for maintaining optimal engine function, as it directly affects the spark quality and combustion process within the engine.

In contrast, unusual fuel consumption may suggest other fuel system issues, low battery voltage is typically related to electrical problems, and clear exhaust emissions generally indicate proper combustion efficiency. These factors are not direct indicators of spark plug wear compared to the condition of the spark plug insulator itself.