Thank you. I never thought of looking at them end to end to see the difference. Take care. BillI don't find the need for the fancy, more expensive plugs. All I've ever used are the regular NGK's and they've always worked fine. I do change them out pretty frequently though, like every 3 to 4K. I find the center electrodes are beginning to wear down by then. The plugs still work OK but just not quite as well as new ones. I consider changing them a cheap "tune-up", lol.
It's hard to see the wear looking at a plug by itself. You need a new one to compare it to side by side .....
View attachment 235817
View attachment 235818
Doing that, it's pretty easy to see the worn down center electrode on the old plug.