Turning up a Detroit, help or hinder?

If the "super overhaul" failed I'd raise heck to get the tow covered. You may or may not because they will probably say it should have been towed to "the closest Detroit authorized facility" for repairs. Still, seems pretty crappy if they don't cover it. As to fuel mileage, I have my Detroit turned up to 515 but rarely drive faster than 65. I average 5.5 to 5.75.

 

Man if they did a super overhaul on that thing and it lasted such little time, I would not bring the truck back to that place! That sucks though man I hope you get it fixed right this time and get back on the road soon!

 

What are the rest of the specs on that truck (trans, ratio, tires)? Please keep this thread posted on how things work out.

I just bought an 05 Century that's getting almost 1 mpg less than the 04 I already had. I suspect about half is due to the newer one being more worn, and the other half from just not as good a spec.

The 05 is 465hp 14L DD, 10 sp, 3.70, with 11r22.5 tires. It is truly a 65 mph truck. Running 60-65 under a load you will get just over 6mpg with a tail wind. Push it up to 70 and you're deep into the 5's.

The 04 is 500hp 14L DD, 13 sp, 3.55, with low pro 22.5 tires. It will get 6-6.5 at 70 mph all day long under a load. Better than 7 mpg if you slow down to <65 and/or have a lighter load.

I'm very interested to hear about not only the mechanical fix for your truck, but also if there is anything else diagnosed that is not related to the mechanicals affecting your fuel use.

 

Where did you get this "Super Overhaul" done and what exactly is a "Super Overhaul"? Running the route you run you have two Inland shops to choose from. One in Carol Stream Il and the other in Gary In. Inland Power Group, they are detroit shops. I would recommend going there due to the fact they are Detroit Shops.

 

I had an 06, 465, 10, 3.55 and LP 22.5's and got in the high 6's grossed out. Others in my fleet with same spec;s but 13 spd could beat that and see 7's.

Something else, if you can swap drivers for a week you can see if there is a different driving style. Is '06 driver progressive shifting? Mant other "driver" factors.

 

What did this "super o'haul" include, parts wise?

 

So was he supposed to take it some place else and pay another shop for anothre rebuild. If detroit is warrenty it, he has to take it there or pay again.

 

I was always told to drive easy for a while on an overhaul.
Also your speed is part of the fuel economy problem. Most trucks and tires are designed to run 55-60 for best economy. I hate to say that as I know beating I'm going to hear for it.

 

You're experience agrees with what I expected. The 05 is a new to me truck and the driver's been in it just two weeks now. So I agree that some improvement will come with his getting used to handling it. I've driven both and definitely feel that the 05 is capable of more, both in terms of economy and power. I'm going to give it some time and see how it works out for the next month or two before spending the bucks to chase a mechanical solution. Plus get a little further past the sting of getting the 04 up to snuff. The dealer I'm using right now has a senior tech that I trust enough to spend a few diagnostic dollars with on a fishing expedition early next year.

My gut feeling is I'll be shopping my own "super overhaul" at some point, thus my interest in the OP's progress on his own fix. OP says he blew a head gasket. If he got an in-frame with that too, I'd expect he ought to get some improvement and curious as to how it works out eventually.