Steve Cole at TTS was questioned about the difference in computer program between Fed Duramaxes and Ca. He ran the tables on his computer and compared the two while i watched. There is a difference. He wrote a program taking in the best of both worlds and we installed it in my truck today. Big difference at part throttle application in mid range. Also got to play with an Edge on my truck and a Quad 165. I then installed the TTS chip (120) and played around. Now i am stock with the updated Fed-Cal. program. I only have 204 miles so far. There is a new turbo down pipe in the works.