Bests & Worsts Reviews from Amazon

Several points to cover. I had it for three days, and here is what I encountered. After downloading the codes to the sim card, and putting the sim card into the unit it started throwing me errors about its inability to read the sim card. Since I was not able to get the unit updated, or the data pushed to my truck, I called tech support. He said files were missing, so he needed to remote control my computer with the sim card installed. Gave him Team Viewer access, and he went to an entirely different location, and pulled down the files. He likewise walked me through the install (very helpful, but obviously tired and frustrated by his tech support position, and that came through in his tone). Got everything set up, and started a 240 mile drive to see how much it would increase my mileage. The unit was saying I was getting 9-10 mpg, where I was previously getting 15.1, so I assumed a reading or tire size error. Got back, topped off my tank as I always do, and calculated the mileage. Miles traveled divided by gallons used (did not use either trip reading, as they are seemingly never correct). My mileage was 11.4. This was a Saturday, so I had to wait to contact Bully Dog until Monday. Told them of my findings and that the unit was again saying it could not read the sim card. He said it was either a bad sim card, or bad unit, but I could not afford to wait for a replacement in hopes of the next one actually producing positive results. So I uninstalled the unit, which is supposed to reset the vehicle to the factory settings as downloaded to the sim card (maybe in this case), boxed it up and returned it. After returning my computer to factory you would think I would return to 15.1 mpg with the exact same driving habits, but my mileage is down by 1.5 mpg. I will be taking it into my friend's shop next week to get him to either return it to factory, or push updated codes. I very badly wanted this unit to work, but it was a disappointment. The shop has one of the best ODBII commercial reader programmers (just over $8,000) and he said the Bully Dog has left the computer in a locked state, and he cannot push changes to the vehicle. I'll take his report and contact Bully Dog in hopes they will help me get back to the known factory state as prior to installing their tool and device.