This was for a 2005 Dodge Dakota 3.7 V6 truck. I am only reviewing my first impressions as I just received and installed one day go. Time will tell about long term, but the immediate impression was that it was a simple install, after I downloaded the vehicle/motor correct tune from the Hypertech website. I drove the truck after install and again this morning and the most obvious improvement right away were the much better shift points as well as when I put the truck in "tow/haul" mode it did a noticeably better job of staying in the "best" gear for the speed and weight. I did not buy for more mpg but maybe that will be a small benefit. Time will tell. However, the immediate seat of the pants reaction is noticeably better transmission management and shift points and better throttle response. Without regards to what might be a few more HP or torque, if all I got was the better gear management and throttle response, I will be satisfied with the results vs cost.

I have used this programmer for about a year and a half. I did not expect a lot with it, but was hopeful. For the amount of money these cost, one needs to be very hopeful.I have put the program on and taken if off many times in the past year and a half. I have tested results and performance and feel as much as I know how to. The number one thing I have determined that I can say about it is that the difference is 'noticeable'. I cannot get more positive or negative about it.I have a 2010 Jeep Liberty. I rated this 5 stars because I didn't expect a lot, after doing lots of reading before purchasing. Also, the KK Liberty has that CVT transmission and shifts strangely, for those that have not driven a vehicle with CVT. The Hypertech cleaned up the shifting some. Also, there is slightly more power with it. I was able to get a solid 5% improvement in gas mileage with the Hypertech, sometimes more. Overall, I am very happy with it and it was worth the money. But, had I expected a lot of power improvement or 15% or more fuel mileage improvement, I would be quite disappointed.The programmer is easy to use. It is simple for anyone with minimal PC knowledge to update the programmer. When programming the vehicle, you have to sit there for a while. I can see some being confused by the instructions (turning the key to 'on' versus 'run'). Setting the vehicle back to stock does not take long. Putting on the power program does, in my opinion, especially when it is real hot or cold outside.Also, for the Liberty, I don't believe any of the specific settings work, is in tire size selection, etc.I have noticed that now since I have 255-70 R16s on steel wheels, the difference in fuel mileage when the program is on or stock seems to be greater.I remove the program when taking it to the dealer. I am still under powertrain warranty so I go to the dealer for more stuff than I will when the warranty expires. Also, I remove it before inspections. In that case, make sure to drive it for 50-100 miles. I have had codes pulled when just setting it back to stock and taking it straight to the shop.I have had a misfire, so to speak, when loading the power program one time. It was not pretty. I do not know what I did wrong, but the KK didn't want to drive well after that. Things were flashing and I was freaking out. I could not get anywhere plugging the Hypertech back in. I say all that to say this ... I called Hypertech and they were easy to talk to and helpful. In short, all I had to do was disconnect the battery and let it sit for a while. That reset things and I was able to use the programmer after that. Those of you familiar with programmers probably would have known what to do. But, it was good to know that Hypertech was good to deal with.At this point, I am trying some other mods on my KK, and looking into getting a B&G PCM flash. So, my days with the Hypertech could be numbered.

After much hand wringing and reading reviews all over, I decided to give this a whirl on my 2007 Jeep Commander with the 3.7L V6, a Rough Country 2" lift/level kit, 17x8 Pro Comp 7105s with Goodyear Duratracs in 265/70/17s. Mostly wanted it to recalibrate the speedo, and make sure everything was good to go with the bigger tires. A little performance boost certainly was welcome for this pig as well!The 1st programmer I received had been used by somebody else, which LOCKS the programmer on to their VIN - Hypertech makes it so you can only program these on 1 vehicle (for obvious reasons)... pretty frustrating to get all excited then get a "vehicle mismatch" code on the damn box you just spent $300 bucks on, then have to wait 4 more days for a new one! After my frustration ceased and I waited for Amazon to deliver another one (which their return/replace program did promptly, even before I had sent the old one back) I loaded up the new programmer on my computer, installed the correct tune, and loaded it on to my vehicle. Install was a breeze, in my haste I did forget to unplug my phone charger, so I deleted the tune, returned it to stock and reloaded it. Don't know how much of a difference that really makes, but just for safety's sake I did it. Took it for a spin around the neighborhood, and it may just be me, but it does seem to have a bit more scoot to it. I didn't adjust shift points or anything but it also seemed a bit smoother that way too. I'll update with MPG gains and perceived performance improvements over time.To the guy who sent the tuner back after programming his car (last 4 of your VIN is 0639) I sorely hope you did not leave this tune on and send it back, as you may run in to problems later if you take your car in to get a tune up at a shop. You may regret it, since you now can't return your car to the stock tune first...All in all, kudos to Amazon once again for great customer service, kudos to Hypertech, and a big thumbs down to the cheater.