Do spark plugs affect fuel consumption?
2 Answers
Spark plugs do affect fuel consumption. If a spark plug is damaged, it can directly cause an increase in a car's fuel consumption. Methods to determine if a spark plug is damaged: Remove the spark plug and observe its appearance. The condition of the spark plug can be judged based on the following color observations. A normal spark plug has an insulator skirt and electrodes that appear gray-white, gray-yellow, or light brown. A properly functioning spark plug has a reddish-brown insulator skirt, 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 signs like blistering at the top, black streaks, cracks, or melted electrodes, the cause of the damage should be identified. After troubleshooting, replace the spark plug with a new one. Additionally, if the spark plug appears black as if smoked, it indicates the wrong heat range was selected or the air-fuel mixture is too rich, or there is oil leakage. Steps to replace a spark plug: Open the hood, lift the engine's plastic cover, and remove the high-voltage wires. Mark each wire according to its corresponding cylinder position to avoid confusion. Use a spark plug socket to remove each spark plug one by one. While removing, check for external debris like leaves or dust and ensure everything is cleaned thoroughly. Place the new spark plug into the spark plug hole, hand-tighten it a few turns, and then use the socket to tighten it further. Reinstall the high-voltage wires in the correct firing order, then reattach the cover.
Spark plugs absolutely affect fuel consumption, and this is my personal experience. I encountered this issue with my old car when the fuel consumption suddenly increased significantly. After inspection, I found the spark plugs were worn out, causing unstable ignition and incomplete fuel combustion, which forced the engine to inject more fuel to compensate. After replacing the spark plugs, I clearly felt the car ran smoother, and the fuel consumption returned to normal levels. It's recommended to check the spark plugs every 30,000 kilometers or so. If the electrodes are worn or severely carbon-fouled, replace them to save on fuel costs and prevent more significant failures. Also, avoid aggressive acceleration during daily driving to reduce stress on the spark plugs.
