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triple axel · 07-30-2010, 09:50 PM

I am a brand new airstream owner (today!!!), and have only owned my 2004 Dodge Ram Quad Cab with the 5.9 cummings diesel (81000 miles) for about a week.

Picked up my 1990 34ft Limited today in Madison, WI and pulled it home to Duluth, MN. I have been getting 18-19mpg with my truck on highway (68-75mph) without the AS. I was only getting 9 miles per gallon on the way home today pulling my 34 footer at 68-72 miles per hour in over-drive. Not much wind.

Had all 6 wheels pulled off the AS, bearings assessed and greased prior to leaving Madison.

THE QUESTION: What kind of mileage do you get with your TV? I was expecting 12-15 miles per gallon? Any thoughts?

Sorry if there is alot of info on this already--couldn't find anything when I searched.

blacksheep · 07-30-2010, 10:01 PM

If you are watching the overhead mpg readout it is not accurate. The only way to know fuel mileage is to hand calculate.

It is very possible to only get 9 mpg pulling at that speed with a stock truck. Adding a downloader or power box will up that figure some.

Godspeed,
Trent

triple axel · 07-30-2010, 10:13 PM

And those figures are based on the overhead readout.

Just to add... it is a 2500 3/4 ton.

NashBuff · 07-30-2010, 10:18 PM

So 9-11 that is the deal.

2airishuman · 07-30-2010, 10:22 PM

triple axel · 07-31-2010, 06:30 AM

Thanks for all the links 2air. I need to practice with my search techniques on this forum. Still getting used to it.

And I should slow down a little bit as well!

Frank's Trailer Works · 07-31-2010, 06:40 AM

I just bought a 2003 3500 long bed 4 door and got the same results as you. I stopped turning the over drive off while towing and my milage went up dramatically. I know it is recommended to tow without overdrive, but I see zero change in shifting on big hills and the added milage makes a big difference.

fstuneck · 07-31-2010, 06:54 AM

We're pulling a 1993 34 Classic Ltd. w/ a 1998 Dodge Cummins 32V. w/105,000. Get 14-15 mpg in OD almost all the time on flat ground (like out the the Black Hills, etc.) Regular as clockwork; almost always 14.something. However, I usually get 19-22 without the trailer. Yours sounds a little low for a Dodge Cummins engine. I don't use OD on hills w/cruise control though. I have a really heavy sprung 2500 2WD, seems highway geared to me. Just for ref for ya.

xonvldz · 07-31-2010, 06:59 AM

it depends what rear is in the truck.it sounds like you may have a 410 rear which equates to this kind of mileage.my stock 2005 excursion diesel gets between 11.5-13.0 towing depending on speed.my truck has a 373 rear gears.i tow with tow,haul mode which has overdrive.gcwr with truck and trailer is approx 18000lbs.

JBinKC · 07-31-2010, 07:01 AM

I've been towing in the Ozarks this summer -- very steep, short grades. In the "tow mode," my transmission temp stays in the normal range, 180 to 200 degrees. I lost a transmission in the same Ozark hills in a Ford Expedition pulling a 4,000 lb boat with the overdrive on. So I keep the overdrive off, accept the lower MPG, and save the transmission. Best wishes, John

Mikethefixit · 07-31-2010, 08:03 AM

Tripple
IF ya wanna get fuel mileage ya gotta get your toes off the fan. Slow that thing down to 60 to 65 mph . Easy away from dem traffic lites and STOP signs. I think you are trying get that Cummins to perform like a gas job and its tellin ya it aint a gonna do it. IT shows it in the fuel mileage.
Keep the RPM's down to 16 to 18 hundred and see the difference. I have driven diesel engines for almost 50 yrs , I do believe I can see the signs. As you can see by the profile we have an F350/7.3 liter Harvester Diesel and it gets 14 around town and 20 highway NOT TOWING. The average towing is 15 to 17MPG depending on conditions.
SLOW DOWN ENJOY THE RIDE and save some money on fuel while you are doing it. Start a little earlier then ya dont have to hurry so fast.
GOOD LUCK

blacksheep · 07-31-2010, 08:20 AM

triple axel, is your truck a stick or auto? What rear end ratio? I can help you get better mpg's if you want.

Godspeed,
Trent

slowmover · 07-31-2010, 09:11 AM

60 mph is The Brick Wall where aerodynamic resistance is the single worst factor.

You'll want to know which engine: mine is a 2004.0 with the 305/555 ISB. Yours "may" be the 325HP motor (which adds an extra injection event and features internal changes as well). The 5.9 Cummins "peaks" for fuel economy on the third generation trucks (HPCR: High Pressure Common Rail) in the 2003-2004.0 period. The 2004.5 begins a slight downward trend as emission controls take force (the 5.9's are better than the 6.7's in re mpg).

The trick to a diesel is to give it what it wants (not what the driver wants) and use as little fuel as possible to get to the correct gear. I keep mine between 1700-1900 rpm for all driving (manual trans) and see high mpg while solo.

I also change air/fuel/oil filters at 6k/6mos during an oil change. Or, if all highway miles I change the fuel filter at 6-7k. Change it often is the point, as the engine is sensitive to either air or fuel filters being dirty. I can do it in about 5-minutes, so I recommend getting the tools/fittings to keep in a dedicated toolbox onboard, as well as 1-2 spare fuel filters (BALDWIN FP7977 ONLY!). Your truck "may" have been converted to an intank fuel pump, so check for this as it tends to be more reliable than the engine mount pump.

Go thru alignment, brake drag, correct WDH rigging, etc. Fuel economy means chasing down all the possible mechanical details. A nose-high truck will do poorly, for example.

Good luck.

I believe this is the best place to start:

http://www.airforums.com/forums/f238...-in-17984.html

.

**GCinSC2** · 07-31-2010, 09:40 AM

triple axel,

Welcome to Airforums.

If you would provide the details of your truck, trans, axle ratio etc that will help narrow this a bit.

My .02$.
The overhead figures should not be used for discussion, use consistant fillup techniques and actual hand calculated MPG numbers.

Any comparison to a different make, or even a different engine series 5.9L 12V, vs. 24V vs. HPCR will only add confusion to this. The Q. is, is your truck getting mileage that similar Dodge Cummins trucks get?

Also details about any mods to your truck or tires all become interesting things to know.

I'm not reporting any mileage on my rig because I have not driven it enough fully loaded to offer any figures. I do get 19 easily on my empty daily commuting. 93,000 miles on my '05.

I'm sure that getting a loaded weight or your rig will be of interest.

There are several dedicated Dodge Diesel forums.

gaylejoe · 07-31-2010, 09:57 AM

I have an 06 Dodge 3/4 ton 2WD Cummings and pull a Safari 25' FB. We just completed our 3 month trip pulling around 8,000 miles. We do not pay any attention to the overhead cousul as it is not accurate. Our mileage is determined by the miles driven between each fill-up. Our average was 14.9 mpg. I got as high as 16.5mpg pulling between Bakersfield and Merrysville, CA driving 55mpg. My wife keeps very accurate records of our fuel purchases and the mileage. Our mileage has not changed much during the last 4 vacations pulling our Airstream over 38 States.

Sometimes the mileage fluacated a lot and I attributed it to the quality of the diesel.
I couldn't be happiers with my Dodge. On the highway, not towing, and using cruise control, it is not uncommon to get 20-23 mph. No lie.