My "new" 2005 - 23.9 mpg

Drove up to register my new 2005, small town up a windy canyon , across rolling wheat fields prairie and back home, 95 miles round trip. Got 23.9 mpg

Cool !

 

is

Is that what the overhead reads or hand calculated? The overhead's pretty generous especially if the truck's got a tuner on it.

 

Don't trust the "Lie-o-Meter"! If it's not hand calculated then not true. The computer is generating that number based on drive the exact way for the rest of the tank. Real world diving doesn't quite allow that. I once had the "Lie-o-Meter" show 60+ after reset and driving down a grade. The best I ever got was between 20 - 22 going down 95 through SC and GA. No trailer or heavy load in bed. Probably having items under a tarp helped with that figure! Anyway, enjoy that "new" to you truck!

 

Lie - O- meter or not, sure sounds good, and fun to brag about what my lie-o-meter syas like everyone else

Ill check hand calculated next fill up like I do with my other CTD

 

Is the truck tuned? Or gave larger injectors?

 

I've heard that the '03/early '04 gets the best mileage being is 305 HP. My experience has been that country driving, or interstate (but empty and 65mph or so) gets me about 21 and sometimes I touch 22 mpg. This is calculated mileage using a spreadsheet to track fuelings and all of the numbers, so its quite accurate over a period of time.

Charles

The bold numbers below were local unloaded miles or interstate but no trailer, the miles preceding the fillup. For privacy reasons I omitted columns showing the location of the fuel stations, and notations on towing, odometer readings. Generally lowest numbers are mountain towing in NC.

I have refilled a total of 85 times and have a running average of 17.382 mpg.

Date/gallons/miles driven/MPG/$cost/cost per mile/station
26-Apr-21 /22.151 /437.1 /19.733 /62.00 /$0.142 /Murphy/WalMart
31-May-21 14.197 236.7 16.673 44.00 $0.186 BP
4-Jun-21 22.007 335.1 15.227 66.00 $0.197 Ingles
16-Jun-21 15.883 261.3 16.452 47.00 $0.180 BP
11-Aug-21 20.973 340.9 16.254 65.00 $0.191 Ingles
11-Sep-21 16.778 252.5 15.049 52.00 $0.206 Valero
21-Oct-21 23.340 342.6 14.679 77.00 $0.225 Buc-ee's
21-Oct-21 6.743 108.8 16.135 24.00 $0.221 Valero
6-Nov-11 24.854 365.0 14.686 81.00 $0.222 Murphy/WalMart
7-Nov-21 24.864 328.5 13.212 86.00 $0.262 RaceTrac
20-Dec-21 10.340 202.8 19.613 35.15 $0.173 Valero
23-Dec-21 22.795 380.6 16.697 72.01 $0.189 Buc-ee's
26-Dec-21 23.535 338.7 14.391 80.00 $0.236 Valero
2-Mar-22 23.815 430.2 18.064 100.00 $0.232 Valero
23-Apr-22 18.088 505.8 27.963 85.00 $0.168 Valero Fluke!! <---- Replaced the lift pump with in tank pump prior to this, tank was drained, bed removed and pump installed.
17-May-22 17.848 240.4 13.469 96.00 $0.399 QT
20-May-22 16.550 259.0 15.650 91.01 $0.351 Ingles
20-May-22 11.787 186.6 15.831 60.00 $0.322 Circle K
24-May-22 15.853 220.6 13.915 84.01 $0.381 Valero
26-Jun-22 14.643 221.0 15.093 77.01 $0.348 QT
29-Jun-22 10.895 147.4 13.529 61.00 $0.414 Ingles
30-Jun-22 18.185 290.8 15.991 80.00 $0.275 Kroger
31-Aug-22 8.212 154.7 18.838 39.00 $0.252 Valero
7-Sep-22 21.386 290.4 13.579 96.00 $0.331 Exxon
7-Sep-22 14.586 200.6 13.753 70.00 $0.349 Exxon
8-Sep-22 18.967 237.3 12.511 90.07 $0.380 QT
8-Sep-22 15.419 216.8 14.061 74.00 $0.341 QT
9-Sep-22 19.691 269.8 13.702 94.50 $0.350 Cenex
9-Sep-22 21.889 236.0 10.782 100.01 $0.424 Casey's
11-Sep-22 14.857 196.4 13.219 75.01 $0.382 Holiday
12-Sep-22 19.879 229.9 11.565 95.00 $0.413 Maverik
15-Sep-22 10.463 232.6 22.231 50.00 $0.215 Conoco
16-Sep-22 14.411 192.1 13.330 67.00 $0.349 Westco
17-Sep-22 15.323 183.8 11.995 72.00 $0.392 Fatdogs
17-Sep-22 10.419 142.6 13.687 58.00 $0.407 Git N Split Sinclair
18-Sep-22 16.459 214.0 13.002 78.00 $0.364 Casey's General Store
18-Sep-22 19.918 267.1 13.410 93.00 $0.348 Shell
19-Sep-22 15.419 217.4 14.099 74.00 $0.340 Exxon
19-Sep-22 15.587 201.9 12.953 67.01 $0.332 Valero
19-Sep-22 16.517 214.0 12.956 72.00 $0.336 Buc-ee's
27-Sep-22 11.392 153.0 13.430 41.00 $0.268 Kroger
29-Oct-22 7.757 132.2 17.043 38.00 $0.287 Valero
30-Oct-22 7.760 113.8 14.665 37.01 $0.325 Buc-ee's
3-Nov-22 18.071 282.1 15.611 86.00 $0.305 Buc-ee's
6-Nov-22 8.801 126.3 14.351 44.00 $0.348 Valero
12-Feb-23 22.865 486.4 21.273 96.01 $0.197 Valero
17-Apr-23 18.432 414.1 22.466 78.02 $0.188 Raceway

 

I agree my 04 gets stellar mileage compared to my 22.

 

It’s more than possible. I have several tens of thousands at 24-MPG minimum (details apply).

No tune, and the readout is off by a percentage at a given speed. Mines high by 11% at 60. So I subtract 1.5-MPG as I drive and am usually very close.

It’s a handy feedback device for seeing effects of winds, heavier traffic, ascent grades, etc. I reset it often on a trip to check to verify MPG hasn’t dropped due to truck issues.

FWIW, re-set on a long downgrade after an hour of driving. It’ll come down to the true number (possible high) a great deal faster than waiting for it to raise to the same number.

Tires are where most screw up. Needs be stock size and design. Highway, or limited off-pavement as was OEM in 2WD or 4WD.. Bridgestone or Michelin preferred.

Alignment and no steering slop is second. Brake drag third in importance.


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4WD Automatic? 65-mph @ 100% on cruise control (Interstate)? Mainly solo?

You’re leaving 10ths behind somewhere. Steering slop likeliest followed by old cab & spring bushings.
New shocks plus better tire design is other. Age on sensors is another.

Trailer axle alignment & brake/bearing pre-set also.

Chasing tenths on the annual average mpg is where things matter most.


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So with everyone's experience, have any of you experienced different fuel mileage depending on which brand of fuel used? Getting fuel locally my truck likes Shell branded fuel and yields a tiny bit more mpg.
Having been on this forum for several years and reading the various posts it seems that the 5.9 gets better mileage overall but loaded both the 5.9 and 6.7 get about the same under load (depending on frontal wind load and terrain of course).
On the interstate my 2009 truck will pull 17 - 19 mpg unloaded, local traveling 15 - 17 mpg, pulling my 31' Airstream travel trailer 11 - 13 mpg. Tuning is stock power but without extra components. Stock size tires. I have owned this truck almost 13 years.

 

I have ever noticed a difference in mpg with different brands, but I have gotten bad fuel before and received horrible mileage. This has happened twice, once really bad.

My 05, 18, and 22 all get about the same mileage… generally within 10% of each other. Sometimes the 6.7’s do better in a given condition and sometimes the 5.9.

Stock for stock the 6.7’s would win anytime the torque converter was locked, driving conditions where the torque converter is unlocked the 5.9 wins hands down due to the NV5600.

With all the mods and tuning my 5.9 had the mileage was better than stock and so was the power.

At the end of the day you can only get so many hp from a gallon of diesel. The slightly better aerodynamics of the 4th gens outweighs the slightly better efficiency of a motor without a DPF, at least that’s my theory as to why they are so similar in economy.

 

I'll never get that with my early G-56. 2000 rpm@ 65 mph.

 

When mine was new, it got 26-27 mpg, several times. I drove 5 hrs each way, at 55-60 mph. Hand calculated. Since then, and 17 yrs later, it has gone down to around 21-22 mpg, at 60-65 mph, with cruise control on. Oh, all unloaded. I don't have the patience to drive any slower, that and people try to run you off the road.

 

Double OD plus tuning for the VVT.

Big truck FE it’s the 12-Auto plus VVT tuning. (2.19-ratio rear gears).

— The driver has become an irritant to the software either a light or heavy-duty truck is run without CC on the highway.

To the OP: a full tank with P/S “Clear Fresh” and silver container fuel additive combined (both for max treatment not maintenance dosed) will get fuel system cleaned up adequately.

New fuel filter recommended, and air filter also examined.

You have to get used to truck, and it has to get used to you (is how to look at early numbers). Set tire pressure to book numbers per scaled axle values.

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Mine still does it at 1,725-rpm (NV-5600) which is right at 59-MPH.

The Aero Wall is at 60.

62-MPH gets all traffic around one soonest. At 64 it’s harder for commercial traffic so one is canceling cruise to get slow passes over soonest (it’s law to do so; both parties have legal responsibilities).

— Avoiding having to pass and absolute maximum time at CC set speed (no changes) goes hand-in-hand with diminishing the aero problem.

Staying alone (vehicle separation distance) is combined FE & Safety practice. Live in the gaps between the packs of the stupids. Get them gone as they overtake.

I do this all day. Doesn’t change my day or travel time to cancel cruise and get others gone. Ran Eastern New Mexico to Wisconsin a few days ago at 78,400-lbs while standing on it (governed) the whole way (tight dispatch).

997-miles and 103-gallons over the second fill.

The successful day is to not ever be in the passing lane or to have used the service brakes. Slow early for changes and run below limit/flow in any other instance as well (metro or construction or whatever). Drop to a speed where rpm constancy is guaranteed.



Ck your dictionary for the picture attached to the word “Stupid”: that’s the guy who at the upper speed limit has vehicles directly ahead, athwart and to the rear of him at any moment on the big road.

The stupids comprise the vast majority. Almost 98%. Happily, they’re easily predictable. Staying away isn’t much of a challenge once one learns to modify HOW to maximize time spent alone.

I’ll have several pass me and then linger just ahead of me (“Oh, oh, get ahead of the beeg truck”), so I just cancel and drift down a ways. Don’t insist on speed versus space. Soon enough they’ll dissipate as a group. Doesn’t matter if that’s five miles or five minutes.

Hundreds of yards back I’ll have resumed my CC set speed. My Average Speed for the day is unchanged in this.

Solo, Loaded, or Towing. Big truck or little’un.

Radio is the cake icing. Distant Early Warning is many miles, not one or two. Takes a high quality installation as the gear used is secondary.

Since the vaxx shot the number of wrecks is up as is the severity attached. Pile-ups used to be rare. But with herd behavior and diminished mental functioning the events on the Interstates are the worst they’ve ever been. It ain’t the cell phones as that’s secondary. Coming up on serious wrecks is now almost daily versus once, twice weekly over 3,000-miles.

Knowing they’ve F’d up the road ahead out of sight is one thing, . . learning how to get around that plus as Waze or G-Maps direct them is the other.

Idling in a 15-minute or 1.5-hr backup just killed FE. Same for following stupids thru a diversion route as they get panicky (“Oh, oh, I am in a hurry”). Don’t be part of the Buc-ees clown brigade all of whom are thirsting for their Bud Light.


FE is in a plan, in actions, and the use of tools.

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And wind can have more effect than anything else.

 

This is a standard cab with Leer topper, Truck has 116K on it, 2wd, 6 seed manual, stock size Michelin Defender tires, Its a tradesman model, so no cruise control. My bold numbers are w/o the trailer (mostly) and is local driving, mixed speeds. Front end has new upper arms/balljoints and was aligned, which improved the driving quality. The non-bold numbers are (mostly) trailer towing, which is un-perdictable as it might be interstate, US highways, state roads, whatever gets me there, a fair amount in the NC mountains, but one long trip to the Blackhills. Headwinds killed one leg of that trip with less than 11 mpg. The spreadsheet has a running average, both mean and median, but since the mileage is mixed between towing and not, its a fairly meaningless number. Trailer tows perfectly and bearings are properly set to near zero freeplay (less than .005" as Timken calls for). The lack of a cruise control does throw a monkey wrench in things but I really don't have any trouble holding a speed well. Drove non-cruise control vehicles for years.

I track the mileage as a gee-whiz thing, it gave me a reason to use and learn about spreadsheets. I have tabs for all of the vehicles, and there is more information than I showed here. Truck and trailer is a "hobby" as travel is for pleasure, so I don't chase the mileage, it is what it is but I can see flukes and trends.

Charles

 

The relationship is between Engine Hours and Average MPH to “get” how fuel mileage works.

I quit chasing MPG years ago as new habits made it automatic.

Cruise Control is set as early as coming down the entrance ramp. Leaving it there is key. The rest is traffic management.

Test for potential high @ 58/9-MPH over preferably a 200-mile Interstate loop back to the same pump. 100% cruise control. This removes aero resistance plus driver error.

Your spreadsheet is showing what you can do.
Not of what the truck is capable.

Have to have the potential high recorded to understand all the other effects. The percentage changes.

Choose the sub-60 MPH rpm and stay on it for test loop (as has no cruise control). Mines at 1,725-rpm as the ideal.

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You’re low on towing MPG as well as highway & city solo.

— Address highway travel speed and use of cruise control (should be 100%). 64-MPH gets you under commercial traffic, and at 62-MPH it’s much easier to manage slow trucks to get past thereby never allowing pack formation (cancel cruise to drop more than 5-MPH below passing vehicles speed). RPM constancy. I do this all day at a higher travel speed. Doesn’t change my day or my ETA to get others around (and it’s law for both parties to keep passes shortest in distance & duration).

Hitch rigging is a normal penalty when not correct where TT should be dead-level after WD set properly to retain Steer Axle scale value solo (truck same weight). PPP hitch adds efficiency, not just elimination of sway potential. 3-Scale method I popularized a dozen years back across RV forums (Ron Gratz formula).

With a TT the MPG penalty is all aero. An A/S should be under 40% where all else is the same. I ran my numbers against HPCR A/S owners with 28-34’ and weighing 8-10k running 58-64/MPH in 2007 when I had an earlier Silver Streak and found I was on the money at 14-16/MPG with this same CTD. 17 is my target today.


Ck (verify):

— TT axle alignment, bearing pre-set, brake drag.

— TV alignment, brake drag and tire pressure. Zero steering slop.


The FE record was set by a Cummins engineer in his personal vehicle. A 2009 IIRC. Deleted and re-tuned. Air box mod. Highway tires. 47-MPG across a full tank of fuel (1,700+ miles) in his daily 25-mile commute. True that he used every trick in the book.

You want lower fuel burn it’s almost all between the ears given a stock or nearly stock truck. That willingness will mean new habits. The operator is 30% and more of FE results.

Bad fuel is noticeable. Ordinary diesel can be bettered by use of additives promoting better combustion and injector interior cleanliness (HOWES Diesel Defender best OTC choice at present, IMO. Run their Meaner Power Cleaner through first. The P/S “service” as precedent to both if you want).

Fuel brand is mainly freshness and additive package. I wouldn’t go out of my way for Shell, but that’s been reported before.

Diesel is refined in this country to be as cheap as possible. Not “best”.

I pay for Howes out of my own pocket. The KW pulls harder, runs smoother. The APU and reefer both run without vibration when I use it (about 5-10k miles or once, twice monthly). With a run that loads Friday and delivers Monday 1,700-miles away it makes for a relaxing weekend.

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Slowmover, I really like reading your posts and have tried to incorporate some of what you talk about, but I have to say I am HIGHLY SKEPTICAL of the story about 47 mpg. Evidence please! My son is an engineer, I will run this by him, but I don't believe anyone ever proved they got 47mpg.