Iridium Power® best demonstrates its performance improvement during acceleration. The world’s smallest center electrode and specially shaped ground electrode deliver maximum spark energy while withstanding temperatures greater than 4000º F. These features combine to achieve higher ignitability and require lower spark voltage than ever before. As a result, acceleration improves in comparison with normal plugs. To increase ignitability, the important point is to let the flame kernel produced by the spark to grow unobstructed. Normally, this can be accomplished by widening the spark gap. However, this causes spark voltage to increase, which has the opposite effect. Iridium Power uses DENSO’s patented U-Groove ground electrode to achieve maximum ignitability while minimizing required voltage.