Two versions of the 3V HT spark plug and a conventional long-reach plug. On the left is the one-piece Champion 7989 that was introduced in 2007. It features a platinum-tipped J-gap ground electrode and platinum center electrode. In the middle is the OE Motorcraft two-piece plug with a U-gap ground electrode of a conventional nickel material with a platinum center electrode. There are premium versions of Autolite HT that are double platinum, but they are still the multi-piece design. The Champion 7989 spark plug is the replacement for all the 3-valve engines. Though the U-gap plug looks kinda whiz-bang and may transfer heat a little better, Champion's tests showed the difference was not significant and that the J-style is less shrouded and delivers a little more spark where it needs to be. Starting with the 2008 models, the 3V head designs were modified to use a long -reach, J-gap plug similar to the one on the right-and maybe that says a lot.