I was redoing the spark plugs on a 2006 Ford Freestar with the 4.2L and replaced the spark plugs with the Motorcraft SP486 (AGSF42FM) plugs which are a "finewire" platinum. I am just wondering if this is the same as "double" platinum, which is supposed to be higher quality than just "single" platinum? The parts.ford.com website states this as an acceptable replacement.
Interestingly, the manual calls for a SP506 plug which is copper, but the factory plugs that came out of the engine were platinum AGSF34EM on one bank and AGSF34EGM on the other bank.
Essentially I am just trying to understand more about this plug. It's a HUGE pain in the arse doing plugs on a van so I want plugs that last as long as possible. Not sure if Iridium plugs would also be an acceptable replacement? Also curious as to what the replacement interval for these plugs should be.
Interestingly, the manual calls for a SP506 plug which is copper, but the factory plugs that came out of the engine were platinum AGSF34EM on one bank and AGSF34EGM on the other bank.
Essentially I am just trying to understand more about this plug. It's a HUGE pain in the arse doing plugs on a van so I want plugs that last as long as possible. Not sure if Iridium plugs would also be an acceptable replacement? Also curious as to what the replacement interval for these plugs should be.