I was looking for something that would enhance the performance of my Chevy HHR and also keep it in tip top shape. I decided to try a set of the Iridium IX spark plugs because of all the great things I've heard about the technology and performance of this plug. Iridium is stronger that any metal used in other spark plugs today which allows it to have the ultra fine center electrode which reduces the voltage needed to create a spark. It also allows for consistant and accurate spark for fast starts and is extremely durable. They mean what they say when they make those claims! This is a great high performance spark plug and I can with out a doubt see it in my daily driving and in my gas use, giving me more power and saving more fuel, which is always good. Even though these are pricey performance plugs, they are well worth it in the long run.