x2. if you have a fouling issue, this plug will not do anything, if not make it worse. problem being, it has too many paths to choose, not keeping them clean unless it fires from one point all the time. however, it may help shield from spark blow-out with the obstructive electrode design. for pouling resistance, you want a small center electrode as found in platnum and iridium plugs. the irridium properties allow enough strength for sizes ranging from .7-.4mm in an open element. also, it has the highes conductivity properties through the core of the material leaving less resistance for the electrons to flow once the surface of the metal builds resistance from deposits. the platnum electrode is nearly as conductive, and has 2x the wear life, but is verry britle, and would not withstand any deto shock. on the E3 plugs, they are just a cheap plug with a new design, and cannot be gapped, but there also is many more factors in the design that may or may not work well/better for alky use. they shouldn't do any harm, using the proper heat range, and do not cost much, if you can find the right ones, so i say give them a shot or 2 and see what you come up with. oh, and o've only seen the bosh +4's perform like total garbage in larger motors, but they do look purdy....