18 mpg Dodge while towing?

Why do people feel that they need to embellish, exaggerate, lie about this?

JIMNLIN wrote:

azdryheat wrote:
Friend claims 18 mpg while towing 35' toy hauler with 2003 Dodge Cummins Diesel with manual transmission. He says he never goes over 55 mph. Is he for real?

I have a same '03 Dodge/Cummins NV5600 305/555 HO 3.73 axle 2wd in a 2500 short bed quad cab truck.

19 mpg while towing a heavy TH ???
...could be a single best tank using the short fill method.
....... watching the fuel guage and guessing at mpgs.

A '03/'04 305/555 Cummins HO does get some of the higher mpgs. Mine has averaged 12-12.5 mpg (pencil figures) over several tanks on long trips pulling my 11000+ lb 5th wheel trailer.

My truck in sig. I've found over a dozen "comps" of others with '03-'04 CTDs pulling Airstreams and vintage kin cousins (as I have) where mpg is 14-16 without really trying. A travel speed range of 55-65 and comps made for non-hilly terrain. This is with TT's from 28-35' and 7-11k in weight.

Manual transmission and 2WD bump it that much higher. I was averaging 15+ at 62-63 mph with a previous identical trailer. This truck, solo, DOES NOT fall below 24-mpg highway (58-mph @ 1,725-rpm) rain or shine, loaded or empty, night or day, traffic or no traffic . . and I've seen 27-mpg numerous times in the South Central U.S. (Order of importance for mpg is: truck spec, climate, terrain and then driver).

So, while 18 is really up there, lets remember that the close "fit" of a 5'er to the truck is a real aerodynamic aid (if that is the trailer type). The air gap on mine is over five feet from truck tailgate to TT front and this is contraindicated for mpg. An aero trailer is pretty well mandatory. So with a squared rear (drop door) and high ground clearance I have my doubts about 18 as anywhere near consistent (the average, not the high of a few tanks).

My truck is also stock. An aftermarket custom tune (Smarty UDC) could well bring my average (21-mpg past 42k miles; 50/50 town or country) up by another 1-2 mpg. Indeed my goal is to hit 17 towing for the conditions conducive to mpg (above).

The only other truck turbodiesel close to an early HPCR CTD is the very first Duramax.

So, a clean sheet combined rig of an early HPCR CTD and an aero 5'er (1989 AVION; 9500-lbs empty; 14k gross) could well hit 18-mpg, IMO. The correct rig and a motivated driver. (As a professional driver I bring tools to the subject of fuel economy that pay. It is more than just slowing down, it is understanding how the tenths of a mpg add up or drain away, Trip planning is central).

Moderator edit to re-size picture to forum limit of 640px maximum width.

I'm on some other forums where the occasional thread comes up about the mpgs for chevy 6.0s. There is always one guy that will post he is getting 20 mpg on the highway with his 6.0. running 70mph. After several posters doubt his story, they will usually re with a cell pic of the on board mpg meter while going down the road. Of course, they have the lastest "tune" and can smoke the tires in 4 out of 6 gears, bla bla. I think one thing is true, some folks just have to justify the money they spent hence, the fishing stories.

This is all very interesting. Was fueling at a Pilot recently and an RV Transporter pulled into the next bay with a Ram pulling a large TT. Asked me what kind of mileage I got, told him we were just finishing up a 17000 mile trip and had averaged 9.7, now this is pulling 17500 Lbs of 5er from Florida to Alaska and back. Fella says WOW, only getting 8 to 9 with his Ram.
So, someone is really telling Fish Stories or really, really bad at Math.

NWKomfort350 wrote:

azdryheat wrote:
Friend claims 18 mpg while towing 35' toy hauler with 2003 Dodge Cummins Diesel with manual transmission. He says he never goes over 55 mph. Is he for real?

I have an acquaintance with an 01 ram 5.9 auto that claims he gets 18 as well towing a tt. I just smile and say oh wow thats really good.
I also met a guy when driving my work truck . Work truck is 14 chevy 3500 dmax. Guy walks up asks how I like it. I tell hi, I dont like it, I love it. He says what about milage towing? I say 12 to 13. He says oh wow! Turns and points at his ram and says I get 18 mpg all the time even towing. Again, I respond with, oh thats really good!
Lol if somebody really thinks they get that type of milage towing these large trailers I just smile. I know I wont be able to convince them they are wrong.
Actually, I met a guy this year camping that gets 12 towing his no slide 29' bumper pull. He drives an early 2000's gas 5.7 hemi...... hmmmm
but he was a good we chatted lots through the long weekend.

Actually he may have gotten one of those Cummins that had a special "carburetor" put on at the factory. It was a special black ops project that the oil companies, government and Dodge was experimenting with. Problem is, someone screwed up and they should have never been released to the public. :E

You were very, very luck to meet three people that actually got them because there was only like 6 built. You might be getting a visit from men in black very soon. They will want to know who now owns those trucks because they want them back very badly. I would be very careful if I were you!

Your a marked man because you know about the 18 MPG towing Dodge Cummins carburetor.

Or at least I have read about it on the internet! :W

sneaky Canucks say "15mpg"... which is 12 miles per US gal...

I doubled my towing mpg over my last truck when I bought my Ram diesel. The bad part was the last truck was a 454 Chevy gasser crew cab 4WD dually 4.10s Ouch, good bye!
2 times 6 = 12, not 18. And sometimes it wasn't even 6.

azdryheat wrote:
Friend claims 18 mpg while towing 35' toy hauler with 2003 Dodge Cummins Diesel with manual transmission. He says he never goes over 55 mph. Is he for real?

I have an acquaintance with an 01 ram 5.9 auto that claims he gets 18 as well towing a tt. I just smile and say oh wow thats really good.
I also met a guy when driving my work truck . Work truck is 14 chevy 3500 dmax. Guy walks up asks how I like it. I tell hi, I dont like it, I love it. He says what about milage towing? I say 12 to 13. He says oh wow! Turns and points at his ram and says I get 18 mpg all the time even towing. Again, I respond with, oh thats really good!
Lol if somebody really thinks they get that type of milage towing these large trailers I just smile. I know I wont be able to convince them they are wrong.
Actually, I met a guy this year camping that gets 12 towing his no slide 29' bumper pull. He drives an early 2000's gas 5.7 hemi...... hmmmm
but he was a good we chatted lots through the long weekend.

I had a similar truck for 10 years, and around 115,000 miles. Best it ever got not towing was a tank at 24 MPH driving through Yellowstone. Towing my 5er and boat was closer 9, but I tow 65 - 70 MPH.

If it gets what he claims, he should keep it forever.

Maybe down hill with the tranny in neutral and the engine idling. Maybe the friend does poorly with math.