Generally speaking a spark plug is a spark plug is a spark plug. Some are better quality than others though. NGK and genuine ford are good. One thing to remember about all spark plugs though no matter how fancy the spark will always travel the easiest path. So in the case of the super 4 plugs it will generally always go down the same electrode....XR8XTC said:It's time to service my XR8, can anyone tell me is it worth buying some other sorta plugs that have claimed power increases etc etc or should i just replace them with dealer supplied items.