I have an 89 Aerostar with 125K on it. I recently put those new Plus 4 4 prong Bosch plugs in, because they were "the best" and any of you that have ever tuned this thing up, know how hard the plugs are to get at... (yeah, I did get them all, and not skip #5)
Anyhow, I changed the wires, Cap, Rotor, etc... as soon as I drove it for
10 miles or so, I heard a slight ping, even when downshifting at higher RPMS... (no load) The car had Regular Bosch Platiums in there before I replaced them, and it never pinged once... It runs great though as far as response, etc...From what I have been reading, the plug is burning too hot for 87 octane basicly. I put 89 in, and the pinging is gone.
Now for my question: I know that prolonged pinging will destroy the pistons over time, and the timing was perfect, so I don't want to retard it, etc... But just because I use better gas, is it ok to run the hotter plugs? or am I still silently ruining the engine? I have heard yes and no... in other words, "if the tree falls in the forest, but you don't hear it, will it still damage the house?" I want to be one of those people that have 250K on their original engine (many aerostars with the 3.0L do out there, so I've been told.... I want to be on that list :-) - Thanks