Does Not Replacing Spark Plugs Affect Fuel Consumption?
3 Answers
Not replacing spark plugs after a certain usage period can lead to increased fuel consumption, so timely replacement of spark plugs can help save fuel. Replacement cycle for spark plugs: Under normal maintenance conditions, they should be replaced after driving 40,000 to 60,000 kilometers. However, this may vary depending on the brand and engine, so it is recommended to follow the user manual. The following standards can be referenced for maintenance replacement: Platinum spark plugs should be replaced at 40,000 kilometers, ordinary nickel alloy spark plugs at 20,000 kilometers, and iridium spark plugs at 60,000 to 80,000 kilometers. Methods to determine if spark plugs are damaged: Remove the spark plugs and observe their appearance color to assess their condition. Normal spark plugs have insulator skirts and electrodes that appear gray-white, gray-yellow, or light brown. A properly functioning spark plug has an insulator skirt that is reddish-brown, with an electrode gap between 0.8-0.9mm and no signs of electrode burn. If the spark plug has oil stains 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, with signs such as 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 mixture is too rich, with oil creeping up.
As a seasoned driver with years of experience, I firmly believe that not changing spark plugs definitely affects fuel consumption. I once drove a car where, after the spark plugs aged, the fuel consumption skyrocketed from 9 liters per 100 kilometers to over 11 liters, and the power became noticeably sluggish. This is because spark plugs are responsible for ignition. If they aren't replaced in time, electrode wear and carbon buildup weaken the spark, leading to incomplete combustion of the air-fuel mixture. As a result, the engine has to inject more fuel to compensate. Over time, this can even cause misfires, engine shaking, or even engine failure. After that experience, I developed a habit of checking and replacing spark plugs every 20,000 kilometers to keep the car running efficiently. This not only saves fuel and money but also extends the engine's lifespan, which is especially important for older cars. Neglecting it could cost you hundreds more in fuel every year—definitely not worth it.
As a car enthusiast, I pay close attention to vehicle performance details. Not replacing spark plugs will definitely increase fuel consumption because aging spark plugs fail to ignite properly, significantly reducing combustion efficiency. When the air-fuel mixture in the combustion chamber doesn't burn completely, the engine control system compensates by increasing fuel injection to maintain power. I've personally witnessed a friend's car experiencing a 15% unexplained increase in fuel consumption, which turned out to be caused by excessive spark plug gap. It's recommended to replace them according to the maintenance manual - typically copper-core spark plugs every 30,000 km or iridium ones last even longer. Delaying replacement not only increases fuel consumption but may also damage other components like oxygen sensors, making it not worth the cost. Developing a habit of regular maintenance keeps your car economical and environmentally friendly.
