Originally Posted by pbfoot
If you use the wrong oil. I have magnetic plugs on my motorcycle and cars. Any oil other than Mobil 1 left a gray residue on the magnets. With Mobil 1 I don't see anything.
I don't know about the "wrong oil" thing. I used Mobil 1 on an Accord I had, and it always had a bit of metal fuzz on the plug. Normal.
5spd w/Steeda STB, e-RMM, Snorkel Delete w/K&N, 110K+ miles