The DENSO Iridium Long Life Spark Plug is the first automotive plug to utilize iridium and is fast becoming the standard for modern high-tech engines. Employing a revolutionary new 360-degree laser-welding process, DENSO has created a spark plug unlike anything on the market today. With this in mind, if your vehicle exhibits bad spark plug symptoms including slow acceleration, poor fuel economy, or engine misfires, consider DENSO for your performance spark plug replacement. Trust in the iridium-spark-plug pioneer to provide spark plugs that showcase unmatched functionality, reliability, and fitment.