18 mpg Dodge while towing?

I call B arbra S Streisand on the 18mpg number. I looked back in my records 98 12V quad cab 4X4 auto tuned to 300rwhp towing a combined 20.5K @ 60mph 13.4 several times around Balersfield, CA on HWY 99. Overall average was 10.5 all numbers hand calc with all tanks filled to the top. Truck would easily get 22mpg solo on a straight freeway trip two hours long.

Not sure what it is but even with the 11 RAM the best numbers are along Bakersfield, the direction does not seem to matter!

The Cummins 12V is avery fuel efficient engine.

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 dad has an 03 Cummins and gets identical MPG towing his 14k GVWR 35 ft fifth wheel. He did say that he hand calculated 14 MPG tank one time... but that was an anomaly... he pulls around 55-60 MPH as well.

Thanks!

Jeremiah

i have tried for 20 years to get someone to prove their fantastic mileage. No one has ever done it. All I tell them is to come hook on my 31W Arctic Fox which weighs around 10K loaded and we'll go to Ohio via I 68 and back to VA. If he can get the bragged about 19 MPG I will pay the fuel bill. It is scientifically proven because there is a formula for BHP and fuel burn and you cannot get more than 115,000 BTU/gallon of #2 diesel. I get 10.9 Westbound from VA to CO on I 81-I 40-I 25-NM 550. That's with a Chevy Duramax turned up to 440 HP and driving 67 mph.
We also have AIRLIIFT air bags and love them.

We had a 96 dodge 360/auto/3.92 that got 9-9.5 pulling a 92 24xx Shadow Cruiser 5er, 5k loaded. That 5er was 7' wide low profile and had a chisel shaped front... VERY aerodynamic. Then I got a 97 ctd/5spd/3.54 and mpg went to 18-18.5 pulling the same tiny 5er. MPG went way down when we went to a med profile 8400gvw 5er. I could get 14mpg if I really babied it. Fast forward... we now have a 15k 32' 5er high profile and a 03 ctd 6spd 4.10 and I saw 14 once. Must have been a short fill, it's usually 11-12 at 65 mpg. Empty and loaded mpg is nearly identical for the 97 and the 03. I have a friend who claims 27 empty with a truck like mine but his is 4wd and has a edge pressure box. I'm sure he is going by the OH rather than actual. I bet your friend is too. Craig

rhagfo wrote:

Cummins12V98 wrote:

Tvov wrote:

Cummins12V98 wrote:
...

I used to get 9.5 but the wife keeps adding weight!

lol, what?! I hope your wife doesn't see that...

Yea I need to quit saying that! It's not too bad seeing out of only one eye. ;)

Since we bought the MS the gross weight has gone up 2K in 3 years of full timing.

So you people on the edge weigh your load once in a while.

Sorry so far past the edge that it doesn't matter and figuring that we may add another 500# to the 5er as we move to full time. I figure as long as I am setting on stock springs and not hitting the upper overloads I am golden!

My 98 4X4 my Son now has is the same as your truck as far as suspension. They really underrated the 2nd gen trucks. My combined load was 20.5K and the truck sat perfectly level and rode really well.

rhagfo wrote:

Cummins12V98 wrote:

Tvov wrote:

Cummins12V98 wrote:
...

I used to get 9.5 but the wife keeps adding weight!

lol, what?! I hope your wife doesn't see that...

Yea I need to quit saying that! It's not too bad seeing out of only one eye. ;)

Since we bought the MS the gross weight has gone up 2K in 3 years of full timing.

So you people on the edge weigh your load once in a while.

Sorry so far past the edge that it doesn't matter and figuring that we may add another 500# to the 5er as we move to full time. I figure as long as I am setting on stock springs and not hitting the upper overloads I am golden!

My 98 4X4 my Son now has is the same as your truck as far as suspension. They really underrated the 2nd gen trucks. My combined load was 20.5K and the truck sat perfectly level and rode really well.

Cummins12V98 wrote:

Tvov wrote:

Cummins12V98 wrote:
...

I used to get 9.5 but the wife keeps adding weight!

lol, what?! I hope your wife doesn't see that...

Yea I need to quit saying that! It's not too bad seeing out of only one eye. ;)

Since we bought the MS the gross weight has gone up 2K in 3 years of full timing.

So you people on the edge weigh your load once in a while.

Sorry so far past the edge that it doesn't matter and figuring that we may add another 500# to the 5er as we move to full time. I figure as long as I am setting on stock springs and not hitting the upper overloads I am golden!

Tvov wrote:

Cummins12V98 wrote:
...

I used to get 9.5 but the wife keeps adding weight!

lol, what?! I hope your wife doesn't see that...

Yea I need to quit saying that! It's not too bad seeing out of only one eye. ;)

Since we bought the MS the gross weight has gone up 2K in 3 years of full timing.

So you people on the edge weigh your load once in a while.

So true on the 'empty'

Even with 4:10 and 4 speed auto I get 18 mpg running 65 mph (drops to 16 mpg 70 mph)

Towing.......I have a smile getting 10.5 mpg running 62 mph
7900# truck----14K# 13'4" FW

allen8106 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 would be surprised if he gets 18 empty. I have a 2013 Duramax and average about 17 empty and I know that 2003 doesn't get as good a mileage as a 2013 just because of fuel mileage improvements in the last 11 years.

Actually, the empty comment is not true. If I drove my 2003 empty at 55, I would get low 20's MPG range. Best tank I ever got with my truck was 24 MPG at that speed.

Towing 17,000 pounds between 65 MPH - 70 MPH would get about 7.5 - 9 MPG.

The 2003 5.9 got some of the best empty MPG of any diesel - if you kept your foot out of it.