Well I finally started having serious doubts about my plugs as my tour seemed to be running like
cr@p above about 4500 rpm. The Bosch +4s were in for about 40K miles but seemed to be going downhill fast.
All the plugs looked about the same:
Dont know if you can see it from this picture, but a few things to note:
- The center electode is about gone
- The gap with the 'missing' electorde has grown to over .060
- The color is a sort of tanish gray, pretty normal I guess...
Conclusion: These plugs seem to run pretty smooth when new, but don't hold up as well as the OEM double platinum plugs. As other have found and posted, The OEM double plat plugs that cost less will run better over a longer plug life.
