Again, it is not the diameter of the wheel that has any bearing on the issue, but the mass of the tire-wheel combination, along with the amount of pressure on the skinny pedal.

 

Rj, you sure you don't have anything else going on? Dragging brakes, injector issues, tire pressures. I know driving my big heavy truck with larger tires it's hard to keep the skinny pedal in mind. I am a big fan of fuel efficiency, if possible on my big trucks. Tuner, deletion and all, it is very hard and I mean very hard to stay off the pedal! It is my greatest concern and goal every time I drive my truck. I'm always analyzing the way I drive versus fuel economy.

 

I just bought a 2016 350 DRW with 68k miles on it in April. It is bone stock with 3.79 gears. I was on here looking to find a way to improve mpg. I have put 15k miles on it towing TT's and 5th wheels from Indiana to Texas and a few trips to other states.
Empty running 75 - 80 on the interstate is 15 - 16 mpg. I was hoping for 18 to 20 empty. The big problem is when you hook a trailer to it. It goes down to 6 to 9 mpg and I try to drive light on both pedals all the time. I just burned 358 gals of fuel last week.

Right after I got it the ck eng light popped P228F unable to learn High. It has factory warranty but dealer say contaminated fuel and wants to replace entire fuel system for 12k no warranty. That was 13k towing miles ago.
Truck has never missed a beat running. Coming back to Texas Thurs from West Memphis AR to Little Rock on I40 cruise set at 77 and never came out of 6th gear up that long *** grade but 7.5 mpg. Few weeks ago same run at 65mph 8.2 mpg.

Anyone have any thoughts, Ideas

Jack

 

You might want to get a second opinion on the fuel system fault, and then get it corrected. That will take care of the truck but the excessive driving speed will need to be addressed.

 

speed limit thru there is 75.......2mph over is excessive........ok ranger rick

 

I didn't know that one was to drive the speed limit, a responsible adult who wants the best fuel mileage will understand that wind resistance increases greatly with increased speed and drives accordingly. You are the one concerned about fuel consumption but not to the point of actually doing something about it.

 

I said in the post I made the same run few weeks back at 65 mph (that was me trying to do something about it)......made .7mpg diff. So your saying what .....I should run 55 and be a hazard to interstate traffic in the quest for better mpg......maybe 45,,

Or how about does that mpg sound on par with this truck. I have Ram owners teliing me they get 20 25 mpg. Not saying I believe them but .......

Or what can be done (aside from Ranger Ricks' Driving School) to increase mpg. Delete EGR?....DPF?....tuner....

It has some sorry *** mud tires on it now....Americus something or other....my first plan is to ditch them see what that does.......they are same size as listed on door

 

If you are getting an honest 15-16 running 75-80 MPH empty on the freeway with a dually you are donig about as good as possible. And your last sentence……..getting 7.5 at 77 MPH I am assuming that was towing while gaining elevation still pretty damn good. There is only ONE thing will help improve that. It has been pointed out………..less pressure on the skinny pedal. Not being “Ranger Rick” as you named another, but just pointing out the fact that driving style will do more for fuel mileage than any gimmick or gizmo on the market.
And BTW, if I drove my RAM the same as you drive I would expect to see similar numbers. Anyone telling you otherwise is either full of **** or bad at math.
Slow down and enjoy your ride! Or don’t slow down and buy more fuel…….your choice. Another thing………wind plays hell with fuel milage with these trucks when towing unless you have a direct tail wind pushing you.

 

Don,

Thanks for the info. Yes, the 7.5 mpg was towing a 14k lb fifth wheel. I made the same run with a comparable trailer a few weeks back and was mind full to stay under 65 mph the whole trip and didn't seem to make a "wow" change in the mpg. It was only .7 mpg for that leg of the trip. I havnt had time to sit down and calc mpg for either of the entire trips yet but it is on my list. I completely understand that speed, wind resistance etc. all play a big part in mpg.

Bought the truck April 7th of this year from a Chevrolet Dealer about 150 miles south of home
specifically for towing RV from factory to dealer.
2016 F350 DRW FX4 XLT 68k miles
Already had air leveling bags on rear and B&W turnover ball gooseneck hitch
Came with 16K Premier Care Ford Bumper to Bumper transferable to me for $75.00 (so hell yes I transfer it)
None of the steering wheel controls worked (clock spring) and the Valance was missing on Front Bumper
Other than that She's Cherry

Stopped at local ford dealer on the way home from buying truck to schedule clock spring replacement under warranty, also were some emission related recall updates needed to be done.
the next Monday I am on the way to Indiana to pick up first trailer for this new side gig. After I filled up in New Madrid, Mo (the second time I ever pumped diesel into this truck), I stopped for breakfast in Mt Vernon, Illinois,120 miles down the road. When I get ready to hit the road again the MIL is on. I called ford dealer back home. He asked is it flashing, how's it running. any other message, (reduced power etc.). Running fine no other message but dash is stuck on mpg because of clock spring. so he say we will look at it when you bring it in for the clock spring next week.

To make a long story short, clock spring has been changed MIL is P228F will not stay cleared, two ford dealers have told me it is just a matter of time until the fuel system craters. I have put 15k on it since MIL first came on, 13K towing. Two dealers say it is bad fuel and poor maintenance not covered under warranty. Insurance company says no way to prove bad fuel from New Madrid, Mo cause no fuel sample so you are on your own. I am still arguing with them but........

So if I replace the fuel system myself, should I delete. That is what I am trying to decide. I can buy 36k more warranty from ford for $3400.00. If i do that no delete?
If I have to drop the tank I may replace it with a 65gal after market.

What are the advantages to deleting EGR, DPF and running a tuner?
1. No need for DEF any more
2. Better Fuel Mileage? If so how much better (driving habits aside)
3. Better durability?

This is what I am trying to figure out. This is my first truck that needed DEF.
I am in general not a fan of big time mods. Seems alot of people do them for show and not for go. Never made much sense to see all the cowboy caddy's here in Texas billowing black smoke behind and louder than a train wreck.
My diesel experiance is with the old 6.9/7.3 IDI so all this EGR bs is new and I am behind the learning curve

Jack

 

Of course this has been a while, but when I was still trucking I only figured my fuel mileage at the end of the month when I did my monthly fuel-mileage report. I averaged about 14000 miles per month and this gave me the actual *average* MPG over time. Each individual leg of a trip would just drive a person nuts because there were too many variables. Even pulling a different trailer would yield different MPG’s. No two days have identical weather conditions which will yeild different results.

Now, as far as deleting goes, I can’t personally attest to anything but from what I have read on bothe Ford and Ram forums; there is not much to be gained as far as MPG is concerned. Any more finding a good tuner is difficult due to EPA giving the tuners hell. If all the emissions equipmen is working properly on a 6.7 (Either brand) is probably going to do more than a delete that may or may not give trouble. Then there is the issue of passing DOT inspections in some areas if they check emmisions equipment. Also, if deleted, how good is after sale support if one has trouble?
Is the person that wrote the tunes still around? If you have trouble with the tune and no support you have a pretty fancy and expensive boat anchor until you can get things sorted out.

With all that, with fuel being what it is today, I would be setting my cruise at 65 and no more. Any money spent would be making sure all of the engine peripherals were in good ooperating conditions, etc.

There is a guy over on one of the RAM forums and on this forum that put over 600,000 miles on his stock 2015 Ram 6.7, and is now racking up miles on his 2022 Ford 6.7 all in stock form. Doing just what you are doing, pulling RV’s from factory to dealer. @Ltngdrvr

Best of luck to you.

EDIT: PS; use highway tread type tires, no “fat oversized” tires for looks. Looks is expensive in more ways than one. Re-install the factory air dam under the front bumper.

 

Don,

i ordered the "air dam" before I ever made the first run.I installed it before I made the second. Done Deal. Not sure how much it helps mpg but looks a lot better. Tires are next. The ones on it have a tone of tread left on them. They are not oversize just pretty aggressive off road tread. I never would have bought them but for now they are what I have.

The fuel system is my big concern now. Hard to believe that as good as it runs that it needs 12 to 20k worth of work depending on which dealer I listen to. Damn thing runs like a beast. Waiting for the final word from Texas Farm Bureau now. Untill I get this straightened out the rest is on the back burner. If I end up doing the fuel system repair myself I will delete at the same time or not at all. If there is no advantage in MPG it would be hard to justify the expense. All the companies selling the tuners and delete equip claim it helps with mpg a lot. Of course they are selling the stuff so caveat emptor.

Just picked up the rebuilt 7.3l IDI turbo long block for my 87 F250. I am swapping it over to a 4x4 frame so will be a minute before its back on the road. I also have a 97 ram 3500 flat bed. The bed is not mitered so the company I pull for will not let me use it.

So do I drive the F350-till it does crater or nut up and start working on it instead of 87 F250? I only pull part time as I have my own business and work maintenance for trane technologies 3 days a week.

Jack

Jack

 

Would you expect then to claim anything differently?
As far as your fuel system goes, first I would spend money on something like Forscan and see what my real pressures are before spending anything else. Also pull the frame mounted filter and examine for any metal flakes in the fuel bowl myself. If any doubts I would be going to an independent diesel shop that specializes in the 6.7 Power Stroke and get a non-dealer opinion. Yes, the diagnosis will cost a few dollars, but likely less than a dealer that may be out to rip you.