Realilistic mileage with a fifthwheel.

[grizz272]

Just curious what kind of fuel mileage I can expect with a fifth-wheel.
1ton 4x4 duramax srw 36 Ft. 13Klbs fifth-wheel. I realize weather, road conditions whether it is flat or hills or mountains all can make a big difference. Generally speaking flat lands like the whole god forsaken state of Illinois.

[hone_eagle]

Detroit to Florida #16,000 8.9mpg @65 2.1 mpg in the hills. 🙂

[3_dog_nights]

Virginia to Flordia and back. 9.4 going south and 8.5 returning north.

[allen8106]

Cummins12V98 wrote:

ReneeG wrote:
We average 12 mpg at 65mph.

Sorry but I would like to tow side by side with you and compare fuel used!

Sounds about right. During a two week vacation to Oregon and back we averaged 12.1 towing 10,500 lbs 5ver at 65 mph. Hand calculated.

[racer4]

Cummins12V98 wrote:

10.5 is the HIGHEST hand calc i see towing at 60 near sea level with no winds. My tanks range from 7.5-10.5.

I am talking AVERAGE over many tanks, NOT using the display.

NOT calling you a liar but this seems very unrealistic even with you I am guessing grossing at 26k or so compared to my 33k.

I am wondering what makes the difference?

Our trucks are mostly the same. You mentioned your higher weight. Other factors might be that you (I think) have two more tires (triple axle) and your FW is taller at the rear (less aerodynamic).

[Cummins12V98]

racer4 wrote:

Cummins12V98 wrote:

racer4 wrote:
10.5-12 mpg at 62 mph with 20,000 miles on the odometer.

I question this also!

Are you saying you have not seen 11.x mpg at 62 mph?

The average of the range I stated is 11.25 mpg.

What speed do you usually tow at?
.

10.5 is the HIGHEST hand calc i see towing at 60 near sea level with no winds. My tanks range from 7.5-10.5.

I am talking AVERAGE over many tanks, NOT using the display.

NOT calling you a liar but this seems very unrealistic even with you I am guessing grossing at 26k or so compared to my 33k.

[racer4]

Cummins12V98 wrote:

racer4 wrote:
10.5-12 mpg at 62 mph with 20,000 miles on the odometer.

I question this also!

Are you saying you have not seen 11.x mpg at 62 mph?

The average of the range I stated is 11.25 mpg.

What speed do you usually tow at?
.

[Cummins12V98]

racer4 wrote:
10.5-12 mpg at 62 mph with 20,000 miles on the odometer.

I question this also!

[Cummins12V98]

ReneeG wrote:
We average 12 mpg at 65mph.

Sorry but I would like to tow side by side with you and compare fuel used!

[racer4]

10.5-12 mpg at 62 mph with 20,000 miles on the odometer.

[Wild_Card]

10 towing 15,500 5th wheel
8-9 in the hills.

68 is my max speed

[ReneeG]

We average 12 mpg at 65mph.

[joebedford]

19,000lb 5er with '11 Duramax - 8.8

[phillyg]

It depends (lawyer speak), but it depends on your towed weight, grade and wind factor. Ten mph seems to be a good average.

[Veebyes]

10.5-11MPG averaged out over multiple YEARS without resetting computer. Flat land, mountains, with trailer (mostly), without trailer, non aggressive driving habits, 64-65MPH most highways, always in TOW mode when towing, often in manual mode in mountainous or hilly terrain, bone stock engine.

[JIMNLIN]

DutchmenSport wrote:
Not a 5er, but my TT (over 10,000 pounds) and length (35.5 feet) would be a comparable tow as far as fuel mileage. On average my 3500 Duramax Duly gets 11-12. Which I don't understand sometimes, because when traveling through the mountains of Kentucky, Tennessee, West Virginia, and even the Black Hills of South Dakota, it will get 13-14 in tow mode, exhaust break mode, and cruise control! Go figure!

Same here with a '03 2500 Dodge/Cummins 305/555 HO NV5600 3.73 gears pulling a 11200-11400 lb 5er in sig. The trailer is a old '97 with a flat square front corner profile.
Every trip we make to NM/CO/UT/WY mountains and passes the Cummins gets a good 1 to 1.5 better mpg than in western OK/KS/TX plains (pencil figures).