Besides Bosch, does anyone have a favorite long-life & better than OEM performing plug?

 

What year is your R55? NGK is the OEM supplier part and what I would recommend running. We have them HERE.

 

I pulled the plugs shortly after this inquiry & found NGK's already installed. They looked too clean & new to be original plugs - got 90+K miles on the car now.

The scrawny little center electrode didn't appear to have any wear or erosion, so I cleaned off the threads, applied some anti seize, and reinstalled them. A far cry from the old days where I had to replace Champions in my International Scout every 15K miles, since the electrodes would erode away to nuthin'