What tuner do you have on the gas 5.9l and how well does it work? Looking into getting a tuner for a little extra power and fuel efficiency. See a lot of different options that all say different things wanted some knowledge from someone that has already put one on the same engine I have and how well it worked and how complicated it was to use.

 

I had a 4.7 myself, and used the Superchips Cortex 3950 for many months. It was incredible. When I wanted more power it made my truck feel like a monster, and when I wanted to save some gas it seemed to help my gas mileage! I'd reccomend it, especially for a 5.9 as it's more powerful than my 4.7 when I had it!