What is an OEM spark plug? I bought least expensive. Champion copper. HAVE to be frugal…tight budget. By the way, sorry about, “myriad of threads”, VCDDriver. Every time I try to reply, I’m told that I have to be logged in, and I AM logged in. Possibly my snail speed computer culprit??? Sorry. Reported problem twice to tech. I am on roommates, Windows 98. My computer got smashed by an ex **%&##()*&^%$##%$%, which the loser never replaced. I’m sorry, what were we talking about???
OEM=original equipment manufacturer, i.e. the same kind that the car was originally supplied with. Normally, the Owner’s Manual will list the type of spark plug and the recommended manufacturer(s). The Champion plugs are probably fine.
A bit of added info: the OEM may not be the same as your car came with. Toyota, for example, uses both NGK and Nippon-Denso as suppliers. Both are considered OEM even though mine came with NGKs.
Also, the part number may vary. The center electrode design code on my originals designated “special design”, however the replacement NGK plug part number code specifies “tapered”. Both are the same, except when TOyota buys them they buy them to the Toyota design specification, which is a “snapshop in time” of the plug the engine design was validation tested with, while NGK sells the aftermarkets using their own catelog number. Same plug.
There usually is no problem switching plugs, as long as the parts’ cross-reference chart says they are approved for your engine. So you went from a platinum plug to a copper plug? Should not be a problem.
The 3800 engine may be a PIA to replace back plugs. Using double platinum plugs would insure never needing to replace them again. However at 200k maybe the champions will last the rest of the cars life if you don’t expect it to go more then 25 to 30k