[petrel]

Based on everything I've read, I should be consistently doing better than 7mph, instead of hovering between 5 and 7. Some research on the trucking forums has given me about 20 different things to check.

I'm going to begin with finding a Detroit Diesel service center I think I can trust and getting them to read the computer setup and make sure all the parameters are right. After that, a search for intake leaks will be next.

Interestingly, one of Detroit Diesel's troubleshooting guides mentions an overfilled crankcase as causing a reduction in economy. I have had the oil changed in the rig three times since I purchased it, by two different Freightliner dealers. Each time they have overfilled it between 1/4 and 1/2 inch over full.