I’m looking for a plug-and-play tuner setup for “off-road use” lol. I’ve already got an exhaust and a few other mods done, but my main goal is better fuel economy. Extra power is fine too, but MPG improvement is really what I’m after since I already have my old 12-valve to mess around with for serious power.
It would also be nice to have something that can switch tunes on the fly. I’ve been searching around and reading threads, but I’m not finding much solid info or a good best diesel tuner harness plug review comparing the different options out there.
This is for a 2011 Ram 3500 6.7. I’d really appreciate input from people with actual hands-on experience. Not looking for the “my brother’s uncle’s cousin had one” type of stories.

Thanks!