Toyota Corolla Poor Fuel Economy – Could It Be Spark Plugs?

A significant in fuel mileage could indeed be related to old o r failing spark plugs. When spark plugs wear out o r become fouled, they can cause misfires, poor combustion, and inefficient fuel use, all of which negatively impact fuel economy.
How Often Should Spark Plugs Be Replaced?

For most vehicles, including the Toyota Corolla, spark plugs should generally be replaced every 30,000 to 100,000 miles, depending on the type of spark plug.

Standard spark plugs: Typically need to be replaced around 30,000 to 50,000 miles.
Iridium spark plugs: These are designed to last much longer, usually around 100,000 miles, making them a great choice if you want longevity and reliable performance.

Do Iridium Spark Plugs Really Last Longer?

Yes, iridium spark plugs are known for their durability and longer lifespan compared to traditional copper o r platinum plugs. Iridium is a more durable metal, and these spark plugs have a fine electrode tip that improves ignition and efficiency, often resulting in better fuel economy, smoother idling, and increased engine performance.
Recommendations:

If your Corolla is experiencing poor fuel economy, it’s a good idea to inspect o r replace the spark plugs. Iridium plugs are often recommended for their long lifespan and efficiency.
Stick to OEM spark plugs e.g., NGK o r Denso as they are designed to work optimally with your engine.

If you haven’t replaced your spark plugs in a while, this could be an easy fix to restore fuel efficiency and overall engine performance.

Let me know if you need any additional info o r help with the replacement process!