(Truck in signature).

Finally had a chance to make an economy run in this truck I bought a little over two years ago; first one direction and then a return.

Just over 300-miles in each direction. Runs were a week apart, but weather was identical; 2 of 3 fill-ups were from same pump. (MPG figure quoted is lower than actual by nearly .5 mpg).

- Elevation change: 10' at either end
(Only grade changes were "bridges" over roads & streams)

- Temps: 85-95F
(Hot & sunny)

- 4-lane divided highways
(changed lanes five times to go around others)

- Seven [7] traffic lights each way; stopped three times at red lights; otherwise geared down. Used brakes only to come to complete stop for rest breaks. Near zero idle time.

- 62 mph elapsed time on outbound (66 mph on speedo).
- 58 mph elapsed time on inbound (62 mph on speedo; 1,800 rpm on tach)

Running 70-mph [66 mph actual] would have only shortened trip by approximately 35" on an approximately 5-hour drive; or, around 10%. I "wasted" that much time loading or unloading the truck.

- No headwinds, only a light quartering wind inbound on final one-third.

- Passed through nations fourth largest city each time, but lucky on no traffic slowdowns.

- Cruise control all the way; no massaging pedal (would have been too much work for this geographic area for maybe a tenth or two).

I will have to make this same run several times over the next few months, so will have comparable figures to work from.

I believe that the fuel saved was approximately [7] gallons; or, at my cost of $2.89/gl, around $20.00.

I expect to make this roundtrip around five or six times before Christmas. If (unlikely), the fuel savings remained the same, the total savings would be a full tank of fuel out of every six.

Works out to just over $30/hour for the "extra" 3-hours per roundtrips expended in fuel alone. Other components, most notably tires, are also reduced in cost-per-mile. Driver is also more rested, alert and is using a wider field-of-view.

- Around 12-cents per mile for fuel.



What's faster than a modded Dodge CTD?

What pulls the hills better than a Dodge CTD under a load?

What stretches the fuel better than a Dodge CTD?

What lasts longer than a Dodge CTD?


Why does anyone buy anything else? (for ride & economy, the 305/555 motor, 2WD and NV-56)



As a side note: I averaged 15 mpg pulling my trailer over the same road at about the same speed. Fuel mileage "loss" of 38% is identical to that of a 1971 gas-motored truck in a review I was reading last week of a trailer like mine; solo versus towing as reported in a contemporary Trailer Life article.

 

Rednax, you've given us allot of info there but one thing I didn't see and the first thing that anyone here will ask, were your mpg numbers hand calculated or taken from the overhead display?

 

It's in the title-24.

 

I've gotten that hand calculated. I was averaging 23.7 mpg.

 

Sweet...... My 03 S.O. with the 47re and 4.10 Gears got 18.5 to a little over 19 MPG at best on the highway at 60 to 65 mph...... Towing was around 13 to 14 depending on trailer weight.

 

My best ever was 24.6 mpg (hand calculated). Ran about a constant 62 mph from West Texas to Houston. Smarty version 3.07 level 3.

MikeyB

 

That's pretty decent for a long bed, the 2wd has definitely helped you out with those numbers! Good none-the-less for a 7-8k brick! I'm curious, was it humid or fairly dry where you were driving (where were you driving through btw)?

I was able to get a little less than 22mpg (handcalc), outta mine with a little tail wind coming from Green Bay, WI going to Cleveland, OH... I was able to drive all 630 some odd miles w/o filling up . That was babying it... she still needs broken in as well w/ only 20k on the odo.

Since we are on the subject of MPG, anyone else notice how the computer gets more accurate as you get closer to the end of the tank? I've started making it a habit to reset it every fill up as my travels vary from tank to tank between highway/towing/city which greatly impacts the computer.

 

^ My overhead seems more accurate if I reset it at every tank. That keeps mine within 1-2mpg of hand calculations.

 

^ Mine stays about .5 mpg off when its mostly highway and up to 2-3 mpg error doing more city/idling work.

 

Mileage was, as always (past 36-years) entered onto 12-column notebook (and why I indicated in first line of post: "truck in signature"). That is what is meant by "logged".

I usually drive 66 to 68 mph (1,900 rpm max) so as to keep mpg highest. 22 plus a few tenths is the norm, but I rarely make all-highway trips. Especially not roundtrips of this sort where the return trip is the same route.

There was an intermediate "tank" in between the drives.

Overhead maxed at 26.0 mpg in Houston on this Corpus Christi::Beaumont round trip and slowly descended, tenth by tenth the next 200-miles. (I was below 55 mph in city so as to not have to change speeds; occasionally 55-58 depending on flow). It usually is within 3/4 of a mpg.

It was all about being steady: no lane changes, no speed changes (or, when gliding into a speed reduced town, getting down early), no variations. Nothing new, nothing fancy, no stupid pet tricks.

Now that I know it can do it, I am hoping that at least one, maybe two of these roundtrips can shed light on the "true" high, solo number.

When I drove dedicated OTR I could tell you within 15-minutes my arrival at any customer when I was first presented the paperwork hundreds of miles away. As well, the exact fuel consumption after I'd covered all the alternates of route delivery work.

Driving for fuel economy is a job but it isn't work.

The 305/555 is the motor to have.

 

I have customers hand calculating and averaging around 24-26 mpg on 3/4 ton 4x4 trucks with autos and the only mods are either none or Flow Pro muffler with a Dr. Performance chip. My truck averages 20-22 mpg on the highway (considering size and mods its really good) .

 

Personally, I still can't get over a nearly 4-ton truck getting this kind of mileage. I remember a work truck I drove infrequently in the mid-70's, razor-sharp tuned 454 in a 4.10 geared Chev one-ton. I'd have backflipped if I could have ever gotten ten mpg in those 55 mph days. The old mans 5,600-lb Cadillac never broke 14 and it had a large displacement but VERY efficient design gas V8. With electronic ignition, and, again, razor sharp fuel and spark delivery I have seen Imperials that could get 16 mpg at 65 mph (radial tires sure help over the old days as well).

I've wanted one of these for twenty years, but could only justify it with high mpg/manual/2WD a couple of years ago for business miles and mainly personal miles. The tax deduction helps, but the proper truck makes it possible.

My actual return trip number -- calculated -- was 25.8 mpg. I used a lower number so as to cancel out any fueling weirdness.

Already looking forward to next trip. Without wind of any meaningful sort it should make a good comp.

 

I've thought 24mpg was obtainable for a while now. It's that I rarely get ideal conditions while driving. A much more reasonable/constant average has been 21-21.5mpg for me with the cruse set to 68mph. Here's a picture of my OH on my last empty round trip to Austin and back (~200 miles).

It's cool you've been able to get more, and I don't doubt it as you've got the 305/555 motor.

 

My overhead frequently shows 21-22 and it hand-calcs to 17-18.

On long trips it'll read 24.5+, but it's actually 19-21.

No mods.

 

ONE TIME, I tortured myself with every trick there is to get 24.3 mpg (hd. Calc.) in my 325/600 QC 4X4. I did it for as long as I could stand others going past me as I backed off for the hills, drafted the big rigs, treated the loud pedal like a raw egg, etc. I did this for 371 miles and then pulled in for fuel so I could check, even though the tank still had lots of fuel. Gotta tell ya.....once I came out of that station, I was on it like a mad dog, and just aching to catch someone who had the audacity to blow past me when I was in my "econo-mode".