14.0 Detroit 60 Fuel Mileage

I have used the search engine on POG without finding an answer. I recently purchased a 07 Marathon XLII with the 14.0L EGR engine. I have owned other coaches with the 12.7L for the last 20 years.

I am just trying to understand what is normal. I am not complaining.

What is the typical fuel mileage that others get with the 14.0. Yes I know that depends on speed, terrain, and towing. I am just having a hard time finding any real world numbers for my comparison.

Right now, I am getting 5.7, driving 65 to 70 in rolling terrain, towing a small pickup.

Thanks for any info.

And please spare me, I would have loved to have the 12.7, but I could not find the coach I wanted with that engine.

My average for 3 years and 25000 miles is 6.3 towing a small pickup

5.7 mpg at those speeds seems about right.

Thanks for the info.

Brad, the other thing that I noticed is the turbo boost seems to run much higher on flat ground or slight grades .

I am getting 7.8 towing a 2022 F150 King Ranch, I use cruise control set at 62 mph.
I have newly rebuilt injectors and top adjustment done with injector replacement
Typically when I start off from a stop I let the cruise accelerate as soon as it will take control.
Yes the turbo boost is more pronunced than on my 12.7.

My 12.7 would get 9.8 non towing and 9.2 towing the truck. I had the top end adjustment done on it right after i boubht it so I can't say what effect the adjusrment had on it. I bought the 14L in Feb 24. The new injectors gave me right at 1 mpg more.

There are other factors like wind, speed and weight that are a factor. I understand turbo boost to be on demand. I'm glad to see the boost high it means the turbo is functioning. Enjoy the drive and be concerned when you get a warning buzzer.

Again, I appreciate the information. In God we trust, everybody else bring data.

I will monitor over a longer period. That will help with weather, wind, terrain, fuel, and other variables. But the 5s were a bit lower than I expected.

On both the 12.7s I owned, I picked up almost 1 mpg when I ran the overhead. Looks like I am going to learn how to get the closet floor out of a Marathon. Should be easier than my previous attempts because this engine does not have Jakes that are in the way of adjusting valves and injectors. This coach has trans retarder.

Oh yeah, I need to check to ensure the fan is not ON all the time, that will kill the mileage.

7.18 average for the last year or so according to the Pro Driver. However, I am not sure how the Pro Driver deals with the generator or aquahot diesel consumption.

Mark

The prodriver does not account for gen or webasto. It calculates mileage solely on engine use.

Thanks Richard

I assumed that it measure fuel metered to the engine but was not positive where it picked this information up from.