I have a buddy who is wanting to increase his mpg's. I own a dodge so I am not really sure what the best tuner for him is. He doesnt want a lot more power, just a tune to increase his mileage. He is also wanting exhaust, I have looked around and I have heard the duramax's are better with a 4 inch rather than 5 inch exhaust, is this true? Also, is the hypertech max econ a good enough tuner to do what he wants?

Thanks for the help!

 

PPE economy xcellerator

run whatever diameter exhaust you want, shouldn't make a difference

 

New turbo mouth piece should make quite a bit of difference too