Diesel Fuel Mileage

What the vehicle COULD do is what’s missing in these threads.

1). Vehicle spec.

2). Climate according to USGS

3). Topography

4). TARE weight (driver plus max fuel & gear kept permanently aboard)

5). A 200-mile loop on cruise control at 59-mph, back to same satin and same pump. Top to auto shutoff.

6). Same; but truck loaded as if for camping.

7). Same; but hitched to trailer (full propane & fresh water).

It’s the percentage change between these that matter.

Gas versus diesel = 33%

Solo (loaded less TW) versus towing = 40%

The factors that can’t be changed make comparisons to others almost meaningless. OTOH, some factors can be changed to minimize fuel burn.

The bad driving I see on the Interstate (and lousy hitch rigging is default) surely accounts for some numbers generated. But who goes to the trouble to learn what’s possible is exceedingly rare.

That gap ISN’T fully covered by fuel type or rig aero (despite claims to contrary).

You want the number that says something, it’s AVERAGE MPH.

The worse the discrepancy between AVERAGE and SET SPEED, the worse will be the mpg (for given conditions).

And unless one lives in the mountains, who gives a flip about vacation mpg therein? How did it change the annual fuel bill? Especially as against the upfront cost of a more expensive drivetrain.

Jayco23FB wrote:
Looking at new trucks (3/4 ton) and considering a deisel. I pull a 6000 pound TT. I am wondering what kind of mileage comparable rigs are getting.

Too many variables involved.

What Brand truck?
Which Engine? (various years have different engine combo)
What year?

Well here is one more to add to your question.
https://www.rv.net/forum/index.cfm/fuseaction/thread/tid/29725805.cfm

Probably cheaper to get an aftermarket extra tank if range is all you are after.

I have a '12 GMC 2500HD 4x4 diesel crew cab as my daily. It is completely stock with 82,000 miles on it, and I usually fuel it with B20. I get 15.7 mpg on my mixed freeway commute, 18.5 on long trips without a trailer, and 12.6 pulling my TT. I live in Oregon so lots of hills. I get about 1000 mpg of DEF.

ScottG wrote:
That is something I really like aobut my diesel; the extended range.
I can go away for a weekend and not have to refuel during the trip.

Me too, as long as it's not over 400 miles round trip.

romore wrote:
X2 I run all day without refuelling as long as I keep it around 55-60, fuel consumption goes up noticeably if I push it.

My sweet spot as well. I never hurry anyway. It is a vacation, not a road race.

Never buy another oil burner though. Payback is too long to be financially sound.

My truck sleeps all winter in a heated garage (along with the RV). Only comes out when the leaves are on the trees.

I just returned from Ashville NC , I delivered 2600 lbs from Tallahassee to Ashville in my Ram Cummins 2500 , got 17.6 going up and over 19 return . Pulling a 24 ft cargo trailer I always get 15 or 16 .

A honest 9 hand calc average all conditions. 33k combined.

My 07 Ram Cummins dually with 4.10 rear end got 17 empty at 70MPH. Towing my 13,500 pound fiver I got 10.5-11.5 all day.