I used the tuner to adjust my speedometer for larger tires I put on my truck. That plus the fuel saving setting increased my mpg by almost 20%. I haven't had time to play around with the other settings yet. It's very easy to use. The whole process including reading instructions took about 10 mins.
Got bully dog have not been able to get it to work ,have talked to bully dog rep, they said they were going to have write a new program for my truck. Still waiting to hear from them so I can program my truck and use the b d x Box they said the Product was new still trying to train staff about product. It actually messed up my truck had to take program out truck would barley run. Now it runs fine without it . Hope new program works!!!!!