[theWeezL]

While the claims of the +4 look great on paper in theory they do little to help performance. A spark will take the path of least resistance, so that will be the electrode that is closest to the core. As they wear this gap changes and a new electrod emerges as the shortest path. The problem is the core is still wearing away all this time as well. The +4's are great if you want a super long lasting maintenance free plug. BUT, if your looking for performance the thing to look for is the strongest spark. The key here is resistance. The lower the resistance, the better the spark will be. To be honest there is nothing new on the market that performs significantly better than a copper core plug. The problem is in longevity. Basically its a trade off...lifespan vs resistance

I am currently trying the new irridium NGK's and I felt improvement over the bosche Platinums that came out (not a fair comparison though as my platinums were toast)