Originally Posted by GTyankee
Precious metal plugs, from what i just read, are to be used only
with WASTE SPARK DIS IGNITION SYSTEM
s, (DIS stands for distributorless ignition system),
Here is the full article from Autolite Spark Plugs, it further explains Waste Spark Systems
Very interesting link to that info, GT. I see one problem, however, as it relates to many/most motorcycles with multicylinders and one-coil-per-two-cylinders. These have a "waste spark" and they have no distributor. Whether they run standard plugs, precious metal plugs with just one point, or precious metal plugs with two precious metal points, there doesn't seem to be an issue of excessive wear because of this. Obviously the precious metal plugs of either kind show to last longer in these applications, and that's somewhat logical. I'm a little curious as to their assessment about electrode degradation because of the firing on the exhaust stroke. The firing of the plug under compression and with a fuel combustion is a tough environment for a plug to be sure, but on the exhaust cycle, I wouldn't think the plug's effort or result is anything nearly as tough on the plug. Granted, on the molecular level, there has to some additional wear with another spark, but when that spark is in a less hostile environment, that has to be somewhat of an advantage.
And GT, there is a clarification in their description of what precious metal plugs are...single-tipped or double-tipped. The info in that Ram site 5.7 segment doesn't clarify which style they're using, so that's still up in the air a bit. When I've used precious metal plugs in a myriad of vehicles over the years, I've always used the dual-tipped version if at all available.