Engine/Transmission (1998.5 - 2002) Too Much Power?

[MCarstens]

I have a '99 HD2500. It has more power than I need, but is only getting 12. 5 mpg (11. 5 mpg with a trailer). I do have a topper that sticks above the cab about 7 inches, but find it hard to believe that is the total problem.

I have taken it to the local cummins shop - "nothing I can do, you should take it to Dodge". I took it to Dodge "nothing that we can do to these things, they're all electronic you know".



Is there something that can be done? Can I buy under-sized injectors?

This morning I noticed the snow by the tailpipe was the color of raw diesel for about a 4 foot diameter circle - should I be concerned about this? It was about -5 F this morning.



Thanks,

Mike

 

[RAJohnson]

Mike is the truck still stock or bombed I would check the IAT sensor, a bad one will effect milage.