Motorcraft Iridium Spark Plug: Enhanced Durability & Fuel Efficiency

Fantastic spark plugs all the way around. Full stars for platinum. They are not Iridium quality and don't last as long, but they are infinitely better than the poor 2-piece SP-519 plugs Ford used before replacing the design with these. Motorcraft makes good stuff. These aren't NGK quality either though. You can gap them regardless of what the stupid box says. I gapped them at .045" for my 5.0L V8 in my F150 and fixed my idle starting to get tougher than I'd like. Don't go with Ford recommended intervals though - these will probably not last 100,000 miles at all. I took my old ones out at about 50,000 and they were still useable but were not going to double that life. Still, for another 50,000+ miles and checking every 10 or 20 thousand miles, maybe cleaning and re-gapping, they are worth every single penny. Just use AMSOIL engine oil and top-tier gas with these and your engine will last a very, very long time. I would say these could last 75,000 or so but I'd swap them sooner anyway unless they just look that good after that long. I haven't seen them go beyond that very well.

One of the four "new spark plug" was obviously used and returned by Simone. Had to make a second trip to exchange the plug. Store manager was very understanding and accommodating. Quality Improvement needs to be more aware of "returns".