Say guys i have the G56 6 speed in my new 06 cummins. I have heard different reports and want to know what one is better and what exactly the difference is and what modifications can be done? Thanks in advance guys. Hay so far the computer is still showing i am getting over 17 MPG with just over 500 miles on it. Haven't had to fill yet to hand calculate.
Say if i put on a ATS intake and a 5inch MBRP exhaust turbo back is it gunna hurt my milage or help?
I will mostly be on slower speed roads?

Thanks