Spark plugs that are worn can negatively impact engine performance and overall horsepower, whereas spark plugs in new condition can increase performance and efficiency. Performance spark plugs, such as those made of silver, are specifically manufactured to tolerate higher temperatures, allowing for a more complete burn, thereby increasing horsepower.
Spark plugs create an electric current of high voltage which ignites fuel and creates combustion, causing an engine to run. The higher the temperature of the combustion, the more fuel is burned in the process. Newer vehicles rely on computers to control combustion and are more efficient in burning fuel. Therefore, replacing factory spark plugs with performance spark plugs in newer vehicles does not dramatically increase horsepower because their engines are already running at peak efficiency.
Installing performance spark plugs is an expensive way to increase horsepower and fuel efficiency. For years, car racers and enthusiasts have employed a more economical solution to spark propagation called side gapping. Modifying the spark plug by excising the end of the electrode arm exposes the center electrode, causing the generated spark to fire directly into the combustion chamber. The gap between the electrode and the electrode arm is reduced by 0.010 inches compared to the factory specifications, allowing for a larger spark.