(This is being used on my 2dr 2012 Wrangler Sport X 3.6L manual)
Man oh man, I did not expect this to do much beyond correcting my speedo and (eventually) correcting my axle gears. Oh how I was wrong.
I've never had a tuner before, I went ahead with this one after reading a lot of great reviews on it and decided to go with it cause... well, I just hoped it was worth it. I received this shortly after having lifted my Jeep with a 2.5" lift and 35s... but the 3.6L manual comes with 3.21 gears, something that makes negotiating the uneven roads of the South Texas Hill Country somewhat of a pain on a daily basis. As mentioned before I eventually regeared, but the gears were on the way and to be installed even after that. So when I got the tuner in I went ahead and threw it on if for no other reason to correct my really inaccurate speedo. I corrected tire size and then set the thing to the Mileage X setting and took it for a spin.
Holy--- THIS is the MILEAGE setting!? Stock 3.21 gears still at this point on a 3.6L manual and it drove a million times better with just this tuner (still convinced there is magic in this thing). After re-gearing it and tuning for the new 4.56 gears my Jeep has some real bite to it! And I haven't even tried either of the performance settings yet!
So is it worth it? Absolutely.
Also it says don't store in vehicle cause heat will hurt it. I don't know about that. Like I said, I'm in South Texas, and it's Summer now, it's over 100 degrees every day and I have busted out the tuner from where I keep it in the glove box a few times and it works great. I suspect this may be an advisement from leaving it in direct sunlight and having to not deal with returns/RMAs from those issues. Admittedly it does not feel very solid, so I handle it like glass, but I don't worry about keeping it in the Jeep.