So I chose to drive the truck over the Jeep or a rental car on our big road trip. Truck was empty except for two of us, luggage and a tool box full of stuff. Almost 5500 miles in 13 days, 94 hours on the road. It was start to finish including all of the running around sight seeing. First tank was awesome, Ridgway to Limon CO, 19.5 mpg. Then 30 mph headwinds running east across Kansas, how does that happen? I ran 5-7 over the posted pretty much everywhere so 75-80 mph. Massive headwinds coming home too, how lucky of me to get it coming and going...lol Truck did great, 14.6 for the trip at around a 58 mph average. No attempts was made to get good mileage, I just ran it as it was, drove like a city person when necessary...

Only minor annoyance is still the 10 speed trans programming being just awful empty. Otherwise the truck was comfortable and capable if a bit huge for the task. Gas ranged from 3.85/gal in Tulsa to 4.49/gal in south Florida. We drove through Colorado, Kansas, Missouri, Indiana, Kentucky, Tennessee, Georgia, Florida, Arkansas, Alabama, Louisiana, Texas, Oklahoma and New Mexico. Great trip, still loving this truck.

 

A gasser? Judging by the 6K tach, yes. That is completely satisfactory gas mileage. I get better gas mileage at high altitude. I am in Denver.

 

I always get better mileage in the mountains. I live at 8000 ft and the speeds are lower, 60-65 limits so my normal driving routine nets me almost 17 mpg. Pushing all the wind we did trying to make time definitely brought it down. I figured on about 15mpg. The truck is on 35" tires with the Tremor valance so it wasn't ever set up for good mpg. It is the 7.3 gas engine. This is about 3 mpg better than my steel body 6.2 truck would do. I am perfectly content with the results.

 

Just curious, did you do a hand calculation or just using the trucks MPG readout?

 

I hand calculated it a few times right when it was new, before the tire and valance changes, it read 0.5 mpg low compared to actual. I did it again after the tires and valance and the one tank I checked it was 0.4 mpg low. I haven't hand calculated it in 20k miles, I figured it was accurate enough for comparisons sake.

 

Maybe yours is more accurate than mine... mine is all over the place. It has read anywhere from 2 mpg high to 1 mpg low... however, my driving is all over the place. To date, most often it was city driving, with occasional longer trips. There has been calculations that's been all highway miles unloaded, some loaded... I don't know if my truck just can't get it sorted based on varied driving habits, but it's for sure not really consistent so I don't trust it and just hand calculate each tank I put in. Anyway, sounds like a fun trip. It looks like you hit every state around MS but never got into MS!

 

If I had to guess it would be the regen cycles the diesel has to run messing up a consistent report. Probably difficult for the computer to predict mileage when some of the fuel is being burned just for the sake of making heat. With the gasser fuel is only used for propulsion so the translation is less complex.

 

I’m sure that adds to it too, although I have taken those into consideration too since I know when it is actively in regen. However I have been towing so much lately I haven’t completed an active regen in going on 1700 miles! Lol.

 

14.6 MPG, average. That's exactly what my truck got as an average for the last 2,500 Kms.

 

We are in the middle of our road trip Michigan to cali and back north to south. On rt 1 in cali getting Mexican food and so far about 15.8 mpg. Can’t afford to go fast at the gas prices over here lol.

 

I just accepted the trade off. It was already 94 hours of driving mostly in 7 days since we took several full days off during the trip. Slowing down to save fuel was less important than the time out of the truck that we enjoyed. Picking up 1-1.5 mpg by slowing down 8-10 mph would have either added a day of driving or caused us to skip something we wanted to see. That was not worth a paltry $100 savings.

Of course gas prices from a couple years ago would have been much more palatable at HALF...

 

Oh when I said go fast I mean go faster then posted speed lol any slower then that is unexceptionable at any gas price lol.