Do Car Spark Plugs Affect Engine Power?
2 Answers
Spark plugs have a direct impact on the power of a car engine. Faulty spark plugs can cause symptoms such as difficulty starting, low power, excessive exhaust emissions, and increased fuel consumption. Severely damaged spark plugs may exhibit phenomena like pitting at the top, black streaks, cracks, or melted electrodes. Methods to determine if a spark plug is damaged: Remove the spark plug and observe its appearance to assess its condition. A normal spark plug will have an insulator skirt and electrodes that appear gray-white, gray-yellow, or light brown. A properly functioning spark plug will have a reddish-brown insulator skirt, with an electrode gap between 0.8-0.9mm and no signs of electrode burn. If the spark plug is covered in oil or deposits but is not damaged, it can continue to be used after cleaning off the oil and deposits. If the spark plug is severely damaged, showing pitting, black streaks, cracks, or melted electrodes at the top, the cause of the damage should be identified, and the fault should be resolved before replacing the spark plug. Additionally, if the spark plug appears black as if smoked, it indicates that the wrong heat range was selected or that the air-fuel mixture is too rich, or that engine oil is leaking into the combustion chamber.
Of course it will! My old car suffered from this last year. At first, I noticed the throttle response was sluggish, and the engine would shudder when climbing hills. Later, when the mechanic took it apart, the spark plug electrodes were nearly worn flat, with a thick layer of black carbon buildup in between. He said it was like a lighter without a spark—gasoline sprayed in but couldn't ignite, so the power just dropped off. Actually, choosing spark plugs matters too. Like the iridium ones I switched to later—smaller electrode gaps, more concentrated sparks, and noticeably smoother cold starts. Spending money on replacing them every 30,000–40,000 km is totally worth it. Now, the RPM climbs much more crisply when overtaking.
