Why call standard spark plugs “copper plugs”?

[PeterPolyol]

Yep lots of 'un-addressed' ambiguities and semantics in the automotive game. One recent one was GTL- very confusing. I once thought it meant a gaseous feedstock for the syncrude- ie methane, butane, etc, but apparently any process involving a gaseous step is GTL. Technically PAO qualifies as GTL

 

[UG_Passat]

Bosch used to make Platinum plugs for the auto parts store shelves, where it wasn't merely a platinum tipped plug. the whole core was Platinum, and Bosch used to brag about it.