The good news: you don’t need to know what a spark plug does in your vehicle to know when you need new spark plugs. What you should know is that ignoring this car maintenance task can negatively impact the performance and fuel mileage of your car. Here’s how to know when you need new spark plugs so you can prevent that from happening:
Poor fuel mileage. Because spark plugs are responsible for the spark that ignites the fuel-air mixture in your engine, spark plugs can cause your fuel mileage to drop. Determine if your fuel mileage is decreasing by tracking your fuel purchases and mileage between each fill up. If your fuel mileage does decrease, let your mechanic know so they can diagnose the problem and lower your rising gas bill.
Slow starts. Spark plugs provide the spark that starts your engine. When that spark is not as strong, your engine may turn over slower than usual. Over time, the gap at the top of the spark plug widens, impacting the spark and causing a slow start. Schedule an appointment to replace your spark plugs.
Engine surges and misfires. A lone misfire or surge is not a sign that your spark plugs need to be replaced, but consistent engine surges and misfires can be caused by old spark plugs.
Sluggish acceleration. If your spark plugs haven’t been replaced and your car is slow to accelerate, it could be a sign that it’s time to contact your mechanic. Depending on the kind of spark plugs you choose, plan on replacing your spark plugs every 30-100,000 miles.
Spark plugs are the spark that ignites the fuel-air mixture in your cylinder, creating the combustion that starts and keeps your car engine in motion. If you wait too long to replace your old spark plugs, you can damage other parts of your car.