Today I got 21.6 mpg on a 173 mile trip at 62 mph on freeway. No towing but had tanks full with 66 gallons of diesel & 16k fifth wheel hitch. Has 25.5 k miles on truck.
I've used Enerburn & Optilube in fuel for more than 10 k miles. I like the results. On freeway I get about 450 miles between regens. Considering regens add to oil dilution, I'm happy to keep them to a minimum. Happy traveling guys & gals.

 

Nice. What tires?

 

They are stock & Michelin.

 

 

It's a 2015 F350 cc, srw, short bed all stock with Valvoline PBE.

 

You re-engineered the truck, do you think that any of the changes have anything to do with fuel consumption? Did you re-calibrate the odometer? Did you verify the MPG by hand calculation, and did the OP do the same?

 

On my 2011, the truck computer calculation (basic screen) while all stock was excellent in my opinion at 99.7% vs hand figures when it was new (eight years ago) with OEM tires (275/65-18 ContiTracs). My record was 22 MPG but I'll call that unrealistic because I had to work for that and not my normal driving habits.

However, those tires were useless to my needs and all of that went downhill as I've run various brands of aggressive 295/70-18's such as the Cooper ST MAXX I have currently. Two specific (one was the emissions update) of the many firmware updates my truck has received also decreased MPG by 1 MPG combined which is significant. My average empty prior to expensive emissions issues and then weight loss was 12.6 MPG and since "improvements" is 14.3 MPG. Mine also has a 300 lbs replacement front bumper which certainly isn't helping positive MPG. Some changes cause significant loses. Mud flaps and window rain guards also impact airflow a little. Towing before averaged 11.4 MPG and towing now is 13.2 MPG. Best guess, my truck has never exceeded 17,000 lbs GCVW (light compared to many here). Most of my towing roads are 55 MPH. Currently the computer is typically 0.2-0.3 MPG low vs hand figures.

Some vehicles do have terrible MPG calculations though. My stock Ford Fusion is regularly 2 MPG high. I cannot understand how Ford managed to mess that up so badly but it looks great to those who don't track manually.

After all of my rambling, point is changes absolutely do impact fuel consumption. Also, forced OEM ECM code changes can as well. I have no idea why I track MPG as closely as I do but I just like having the data.

 

I drive my truck very easy. I want it to last for as long as possible. When I tow my 11.9k fiver I usually keep it at about 60 mph.
My trip yesterday was kept at about 62 mph for max mpg. I'm retired & on shorter trips I don't push it. Above that speed it drops like any other vehicle.

I used to hand calculate but found there's no need. At 25k miles, I guess it's broken in now & working at it's best. I know the Enerburn & Optilube Summer Plus is giving me the higher than before milage regens.

 

 

you actually made me laugh out loud reading that.

 

 

21.6 mpg is pretty good.

My 2001 7.3 Excursion would get 21-22 on the highway with 250k miles.

 

Last year I had a 50 mile one way commute to the school I was building. Other than a few blocks from my house to the freeway onramp. it was pretty much all freeway on the drive.
Some days because of traffic, I held a steady 55 mph and would see 22+ mpg displays for the trip out. If I left it parked for lunch and drove the same 55 mph home, I could see 22-23 mpg for the 100 mile commute.

It didn't take much chasing at lunch with town traffic lights and stop signs to bring it down to 16-17 mpg for the day.

Any day that I got on freeway and held 70 mph was a 18 mpg day. and if I held 75 mph it was 17 mpg

So for me, Speed makes a HUGE difference in my mileage

 

You got me good with that one, I needed a laugh. Ya back to reality, I don't think I'm quite getting these numbers either. My '13 F250 srw ccsb 4x4 with 3:31 averages 16.8 city and highway which is still pretty good. I've gotten up to 23 mpg on a flat stretch with a light tail wind at 55 mph on one trip according to computer but you would think I could do better than most with that 3:31 rear end. I run the PM22A, it's cheap and can grab it conveniently from a dealer that's near my work. I ran Archoil ar6200 but wasn't impressed with regen frequency and it did something really strange with my truck's exhaust filter read out; it might say 75% or just whatever % full on way to work on highway then I'd drive around town at low speeds and it would drop down to 35% full ,then on the way home at highway speeds again it would start jumping back up to where it was that morning. With the PM22A I get slightly longer intervals between regens and actually get some passive regen at 75-80 mph, I would soot up fast at those speeds with the ar6200 and go into regen frequently. The exhaust filter % doesn't jump around either with the PM22A.