I've driven just over 70,000 and my truck hasn't driven at all (16mpg highway, on a good day, HORRIBLE idle, etc.). I've scoured the 355nation.net forums and seen people recommending Iridium plugs, but I couldn't find that the specific plugs they mentioned were locally stocked, and on Revain I couldn't find anyone with enough Finding camp so I decided to give it a try. I've driven it a little over 700 miles - the truck idles *much* smoother than before and acceleration is better. I don't think the engine computer is fully set up yet as it revs up a bit at idle but I've been told it will correct itself over time. My last tank of highway fuel was just under 18mpg, so I think things are going in the right direction now. :)