Over the past 45 years or so, I've seen just about every spark plug design imaginable, and I'm not convinced any of them offer any real advantage over conventional plugs, especially on a non-electronic ignition! The plugs I've been most successful with are AC commercial plugs, with a conventional one-piece ground electrode, but both the plug tip and the ground are considerably larger than normal. We've used these plugs on high-RPM race engines with more than twice the lifespan of regular plugs. The plug part number will have a "C" prefix, for instance, "CR45TS", instead of the normal "R45TS" for a regular plug. They're designed for delivery trucks, etc., with lots of stop-and-start driving, and heavy loads. On a regular engine, they last just about forever!
The split-electrode plugs, Platinum tips, etc., are "P.T. Barnum Specials". Like he once said, "There's a sucker born every minute!" Don't waste your money on gimmicks!
Jerry
