diagnosticator1

That would be my suggestion as to why the "fresh" engine response with the new plugs, goes away gradually, from the 'trodes eroding and the gap becoming wider than optimum when new.

diagnosticator1

Yes, the source of the "copper plugs are the best" misinformation.

T-dot B6

would the BRK6E's or 7E's make a difference with stock boost? TIA

T-dot B6

then what is the right or best plugs?

diagnosticator1

by many variables, and specific conditions each engine operates under. Every individual engine, experiences different conditions in operation, that will influence the "best" plug for that engine, used in the operating conditions usually existing, and the specific engine tuning, and driving style of the owner. The plug tip must not get too hot, but must also stay hot enough to not foul out. Other than those two primary criteria, all other plug properties are selected to minimize the compromises, while obtaining the best ignition performance possible. Additional requirements for wear resistance, and general durability are important considerations also.
One example in compromise: Multi-ground electrode plugs are not the best choice for best ignition of high output tuned engines. Because the multiple ground electrodes, shield the spark kernel from the fuel/air mixture, compared to the relatively open single electrode type plug. But, multi ground 'trodes, provide much longer service life, while helping to prevent misfire damage to the CAT at extended change out intervals.

neverfollow01

thank you for the bonus

diagnosticator1

F5DPOR Bosch Platin.

diagnosticator1

"I also have read that the iridium plugs are not as good for our cars as was originally thought but I don't know if this is true or not."

No, this is not true. The alleged evidence supporting that claim is fundamentally flawed, and factually incorrect.

diagnosticator1

If there is any appreciable wear/mileage on the plugs installed now, then yes, for sure.

Tgr_Clw

WW