[ripp_jr]

truck getting poor fuel milage new engine and turbo doesnt have but about 10000 miles on it any suggestions

[BanditsCousin]

What is bad fuel mileage>?

Anyway, it still may need to be broken in. I get 5.5 out of my 500 ISX in a T600 pulling HHG. Numbers would elp me to see how "bad" you're doing.

[tracer]

You can do a Dyno at Cummins. They can tune your fuel settings and horse power. I just did this and the truck pulls much better plus I have a feeling the fuel mileage has improved too.