Most 3.7L's that we done tune-ups on had Champions, but for the record we haven't done a tune-up on a Nitro yet, so I'm not saying Jamie's wrong, he most likely see a change at the dealer level before I would in the aftermarket. That having been said Champion plugs do crop up in unusual places, we've done tune-ups on Kia/Hyundai's with them and a couple of Aveo's had them as well. On the other side of the coin we've seen VW's every so often with NGK's from the factory in Brazil as well. Pull a plug and replace it with the same plug that it came from Chrysler with and you won't have any issues, switch to something else and you may have problems.