Ok, I'm probably going to get flamed here, as I see most of you love the good old school copper, but I use Bosch platinum 4 plugs in my '98 ram 5.2. Now I'm not a guy to throw away good money, so trust me, at over $5 a plug, I wouldn't be using these if I didn't truly feel a difference. I don't have any dyno data or anything like that, but the difference I feel is mainly in a smoother idle from cold start. I have 2 older generation trucks, my Ram and a 91 chevy suburban, and everyone always says these engines don't like the muti electrode plugs, and don't like platinum, etc... but I honestly wonder how many people have actually tried them in their older 8 cylinder vehicles? Both of these trucks are garaged, and not driven daily, and with standard style plugs, I would notice a little roughness, almost like 'camming' for the first minute or two when they were started after not being driven for a couple weeks, after switching to the platinum 4's several years ago, this all but disappeared. Even on cold mornings, the idle is very smooth right from the start, and the acceleration seems just a tad smoother also. I'm not even sure if the acceleration could be measured, but it's the kind of thing you notice if you have owned a vehicle for a long time and are used to the way it drives.
The funny thing is, I also have the MSD AL-6 ignition, and MSD dosent recommend platinum plugs with their setups... but I have found they work great. Supposedly it's a wear thing, the MSD ignition is supposed to wear out platinum plugs too fast... not sure about that, because I change mine every 20,000 or so anyway... but as far as performance, they run just fine. Plus, I'd say in a higher mileage vehicle they would be good too, because they have 4 ground elctrodes, to me this might make them more resistant to fouling. I'd say give 'em a try, I have found a lot of stuff over the years that works pretty good just because I was willing to experiment a little and think outside the box.
Dave
