ok let us beat the mpg horse some

[Clb]

In general
Max boost set @ 15 psi
Cruising @ 60ish 6-8 hundred with an easy spoolup
Max egt seen ( ang I tried) is @1000-1100 deg read @ # 8 cyl
60-65 mph in cali traffic so I don't get rearended.
I This is coastal terrain so combined mix of
Rolling hills
Valley floors
and some twisty canyons.
It's not picky about drive style nor speed.
Except for the fact that the new calibration has way more fueling capabilities.
But the old and new pumps are almost even on mpg.
Power not so much...

 

[Clb]

I run on WMO......my speedometer doesn't work, so my odometer doesn't work, I basically pay nothing for fuel, so if I get 6mpg, it doesn't matter, but I "feel" like I get 12-15mpg, but that's baced on emotions not facts.....good luck keeping this scientific, I promise not to derail the thread with a discussion of "performance".....my N/A 7.3 dually doesn't "perform".....it does "go" though......i "feel" that it goes well....

How do you achieve this?

The 7.3 PSD pump makes 55-60 psi unregulated, so it holds 6 psi with a regulator just fine

What regulator did you use?

Typical derail fodder.

Im putting the oem mechanical pump back in if the holly fails.

 

[KansasIDI]

What regulator did you use?

Holley, I don’t remember the part number

 

[Jesus Freak]

Typical derail fodder.

Im putting the oem mechanical pump back in if the holly fails.

Lol, I just spoke my piece....wasn't trying to derail....

If you can score a decent one, mechanical pump is best. I had high hopes for idiots chebby pump......

 

[lotzagoodstuff]

1990 f350 cclb 4x4. 33s E4od 3.55 gears 7.3idi banks waste gate. I almost never run empty but when I do I get around 23-25mpg on flat ground at 60mph in 4th/OD Usually towing the 10.5k horse trailer around 12min at 55 in 3rd. Remember speed kills. The speed limit back in the 80s-90s was 55 and too going it was 45. So slow down. Wind resistance is a very real thing.

What's the polite way to say I think your mileage calculation is suspect? I'm going to say I'm skeptical.

My cab and a half ZFS was pretty similar to your set up, albeit with 4.10s and I'm sure that your 3.55s definitely help. I ran Portland to Seattle many times at 60 MPH in the right lane the whole way. Never did I see anything close to 20 MPG, with summer fuel (winter was measureably worse) always with a double dose of Howe's or PowerService.

I will also agree that speed kills, but so does weight, and there's nothing light about a CCLB, or the transfer case that you are spinning, and E4ODs are not exactly efficient transmissions. Fill up, run your route via GPS and fill up again from the same pump and calculate your actual mileage. If you have a number that starts with a 2 for MPGs, you should quit your day job and tune IDIs for a living. Sorry for being so skeptical, but if V8 IDIs were this good on fuel I'd still own one.

 

[Dirtleg]

I will tell you honestly what I have gotten when I tracked my mileage over any meaningful distance. You can call me a keyboard warrior if you want and dismiss these claims. Your choice. All mileage figures are highway driving only. Reason is because that is what I had available mostly. Elevation at home hovers around 1000ft. Speeds 65-70 mph typically.

Truck is a 93 F350 4x4 with 33's (285/75-16), E4OD. 3.55 gears. Non turbo, rebuilt injection pump purchased from International dealer near my house. Mileage was about 230K at the time.

In April of 2008 I pulled a 14.5K gooseneck trailer (Yes it was weighed) from Houston Texas to Lynchburg VA. Route was I-10 to I-65 to I-20 to I-85 to I-40 to State Route 29 into Lynchburg. It was a slow operation and I maintained 65 when I could, the best I could manage otherwise. Hand calculated mileage from start to finish was 11.6 MPG.

Over the years I installed a Factory Ford (ATS) turbo and Moose pump. Made a 3" Down pipe into a 4" straight exhaust. Also switched wheels and ended up with a 275/70-17 tire (32")
At one point the advance lever arm broke on the Moose Pump and I threw the international reman back in. I was seeing 20-21 MPG running empty at that time.
Once I fixed the Moose and threw it back in mileage dropped to 17-18 typically.

In June-July of 23' my son and I took a trip to Moab Utah. Truck was too cramped (Std Cab) with 2 dirtbikes, luggage etc. So I bought a Single Axle 6x10 enclosed trailer while there. It's tall inside as at 6'4" I can stand straight up inside with room to spare. It makes a good sail. On the way back from Salt Lake took I-80 to I-29 to I-70 to I-64 to I-77, Rte 460 to I-81 to home. Trailer weight about 2500 lbs. (1200lb trailer weight, 2 dirtbikes. A Honda street bike, luggage and stuff.) Speeds in the 75-80 range. Mileage was 10 mpg average.

My opinion is anything with a Turbo and higher output pump will suffer from a mileage perspective. Also gear ratio. 4.10's will not get the mileage of a 3.55. Is the trailer an open or enclosed? All affect things.

But if the best you can get on level ground and low elevation at 65 is less than 15 unloaded, I would swap a stock pump in and see how that does, then figure the best path forward if mileage is the main goal.

 

[Clb]

Thank you for that.
I need to look at the only highway run up 5 in cal and see what the old pump did as it was slowly getting worse.
You are right about the extra fueling,

I've not gotten 15 iirc ever.
I ran the grapevine on hwy 5 outta la and got the best mpg to date @37k on the clock traveling with traffic.
Doing a gps run is a good idea...

Eta
Are you guys actually compensating for the tire sizes and transmition / final drive gearing?

11.6 @ 65 with15k# on the pin is pretty good.

You must be registered for see images attach

Dry weight is 6k

 

[Dirtleg]

Pulling a 5th wheel will have just about anything in the 9-10 range. Lots of wind resistance.

My 2019 Titan XD Cummins, which will honestly get 21mpg on level highway (Unless it regens, then all bets are off) only gets 10mpg pulling my 30ft 5th wheel which weighs <10k.

I hope you find some relief to your issue.

 

[Black dawg]

Do you know for sure that the tank valve isnt returning some fuel to the other tank?
Are you sure your odo is correct, not based on speedo accuracy, but actually matches miles travelled?

You really are not doing much if any better than 460mpg......

 

[Clb]

Yea my gripe exactly...
The truck is oem original, stock sized tires cooper street treads, per the data plate, sub 60k miles, fresh alignment, tires @ max psi the 5er is a wind sail but it's the same exact setup that I've used for all the testing of mpg.

7k trip to Ak n back garnered ( I'll be back with the numbers later).
Eta I lost the recipts for that trip
I've not used gps so I'm relying on the ferd odometer but even if it's off 3% on a 120 mile trip that's not much
..thanx guys

 

[Clb]

My 2019 Titan XD Cummins, which will honestly get 21mpg on level highway (Unless it regens, then all bets are off) only gets 10mpg pulling my 30ft 5th wheel which weighs <10k.

Ive been interested in those, what happens during regen, does it just waste fuel burning off the cat p e e ?
Drag it actually kills mpg, the epa at its finest right there...

 

[ttman4]

Well thru most of the '90's, when Bessie, my '90 CCLB Dually, was new & thru most of the '90's I could get 18-19-20 round town daily driving. 235-85x16, ATS 088 turbo, etc etc

She get 100-120 K on her & I get down 14-15-16 so I get pump & injectors rebuilt at place back down there Dallas, Tx over on Regal Row.
They were ones that installed my ATS 088 Turbo & exhaust @ 400 brand new miles.

On trips back & forth from Or to Tx I get 19-22+ MPG rolling along 60-75 MPH.
Going up pulls just keep steady pull, rolling off other side let her go up to round 70-75MPH.
(Don't know how I never got ticket.....Radar Detector helped!)

Long bout early 2000's mileage kinda started going down hill.....
Now maybe 13-14 at most.
Last trip 3 yr ago going back to Tx, pulling HEAVY loaded trailer to & from, running round down there, then back to Or.....bout 5500+ miles I maybe got 11-12 MPG!!!!

Few yr ago I put that '94 Factory IDIT engine in Bessie and milage really not changed much from my IDI with the ATS 088.

Bottom line, in my opinion diesel ain't what it used to be!!!!

( I been looking on Amazon for a new style MAJIC CARPET, those kind we used to joke about when we were kids......those kind that fixing to become real!! )

 

[Dirtleg]

Ive been interested in those, what happens during regen, does it just waste fuel burning off the cat p e e ?
Drag it actually kills mpg, the epa at its finest right there...

Yeah the regen is less than ideal. And I am not convinced the fumes from the DEF burning are safer for the environment than the carbon being trapped and burnt off in the DPF. Carbon is not a greenhouse gas. Falls back to the earth.

During Regen I get about 7mpg. It typically regens for 25-30 miles of highway driving. My experience is I burn an extra 3 gallons during the regen process. So every time it regens, I lose $10-12. Oof.

 

[Clb]

Wholly
Crap
Yea and the regen garbage is SO eco friendly

 

[KansasIDI]

Yeah the regen is less than ideal. And I am not convinced the fumes from the DEF burning are safer for the environment than the carbon being trapped and burnt off in the DPF. Carbon is not a greenhouse gas. Falls back to the earth.

So, the DPF (diesel particulate filter) and SCR (selective catalytic reduction, the thing that doses DEF into the exhaust stream) are completely independent of each other. The DPF stores soot until it gets to a certain fill level, and then increases inlet temperature, usually with a fuel injector just ahead of the DPF in the exhaust stream, to cook all of the soot into ash, which has smaller particles than the ceramic filter media, allowing it to blow out and deplete the filter level. I don’t recall the chemical reaction that occurs, but this actually does ‘reduce’ emissions impact.

SCR, and subsequently DEF, are strictly chemical, turning much of the exhaust gases into water vapor… in theory. In practice, the dosing rate is usually sloppy, and much of the urea in the DEF doesn’t atomize properly and often comes out of the exhaust without being emulsified. There are two main reasons the dosing rate is so imprecise. One, DEF is caustic and crystallizes very easily, causing buildup, on what are usually plastic components, as it tends to react poorly with metal, that being the main reason the DEF injector is a common failure point, as there are metal components within that injector, although most of it is usually some sort of ceramic. The properties of DEF also result in it being a terrible lubricant, which is why DEF pumps don’t tend to last all that long, usually just over 100k miles for the pump and injector, give or take 30k miles.

The other reason the dosing rate can be so imprecise is more specific to vehicles built after 2018, which, when a fault is detected, usually attempt to increase dosing rate, rather than average it like pre 2019 vehicles usually did.