Looking for MPG (UPDATE)

Dragging my TV across Nebraska, with its 75 mph speed limit, I get ~7 mpg's (stock 70 classic duramax diesel at the time) Back in Cali and its 55 mph towing speed limit, I usually get 10-11 mpg's. That is about 1 mpg for every 5 mph, those are multi tank averages..

Previous vehicle was a 2011 F 350 dually with the 6.7L diesel, 3:73 gearing.

Almost apples to oranges comparison here, cause a SRW vehicle is the one in question here.

But, I did notice the truck was real particular to speed and the resulting MPG's I got with it. If, and it's a huge IF, I drove between 55-60 MPH, the MPG's were the best, but then, I rarely ever drove that slow.

kopy kat wrote:
my '12 6.7 will average 15-16 in town, 18-20 open road not towing (at around 70 mph) and 14 while towing my 9500 lb. FW.

I tow at maximum 60 mph, have 3.55 rear end and by the way most of it is either done here in the Sierra Nevada Mountains or crossing them at 8,000 elevation.

My combined weight is about 19,000 lb. (+- depending on load).

I run 10 ply Maxxis tires at 80 lb. pressure.

And I also keep complete records of fuel usage, so I know my figures are accurate.

Just saying...Larry

That helps because of the elevation here in Colorado up to 11000' or 12000' on some passes

my '12 6.7 will average 15-16 in town, 18-20 open road not towing (at around 70 mph) and 14 while towing my 9500 lb. FW.

I tow at maximum 60 mph, have 3.55 rear end and by the way most of it is either done here in the Sierra Nevada Mountains or crossing them at 8,000 elevation.

My combined weight is about 19,000 lb. (+- depending on load).

I run 10 ply Maxxis tires at 80 lb. pressure.

And I also keep complete records of fuel usage, so I know my figures are accurate.

Just saying...Larry

Average high teens not towing, approximately 11 not. I've owned 2 now and both get roughly the same mileage. Looking for fuel around 200 miles when towing.
I try to keep my speed around 60 mph when towing.

crshman wrote:

4x4ord wrote:
My '11 with 20" wheels gets about 17 miles/US gal non towing. This is based on a long enough trip to include a regen. Summer time I might get 19 mpg. Towing I get anywhere from 5 to 11 mpg depending on what I'm towing. 11 towing the Rv....about 23 - 24000 lbs gross combined weight.

How fast are you driving loaded and unloaded to get those numbers?

I calculated FishOnOne's average speed to be 55 mph from his picture.

I drive my '14 F250 6.7 with a lead foot around 80 mph and I see 15mpg unloaded on average.

When I pulled my 14k 5vr doing about 70 mph I was around 8mpg.

Wind and elevation both make a huge difference to these trucks. A grade change that you wouldn't notice in a car can effect the fuel mileage of a truck very significantly. The best is to average the mileage; there and back. (At 60 mph a 24,000 lb truck/trailer combination climbing a 0.5% grade would require 19 additional HP over what it would take to pull that load on a level surface. You could expect to burn an additional 1.25 gallons per hour of diesel climbing at that slight rate. So instead of burning 6 gallons per hour you would burn 7.25 gallons to drive that same 60 miles....which would be the difference of 10 mpg to 8 mpg. Climbing a 0.5% grade for 60 miles would mean an elevation increase of about 1600 ft over the trip. If your trip has a lot of up and down you might not see an overall elevation gain but still use power to pull up the grades. Then rather than regain the energy coming down you might turn the energy into heat by holding the load back with the engine or brakes)

A side wind can cause as much or even more drag than a head wind on some vehicles.

N-Trouble wrote:
And yes, there are lots of "claims" out there as you put it on the internet. Imagine that...

Just like the claims you read on here that say the opposite, right?

majorgator wrote:

N-Trouble wrote:

majorgator wrote:
FWIW, a very good friend of mine pulls his 5th wheel (I'm guessing 9K to 10K, not a huge one) with a 2013(or 14) extended cab, short wheel base, 4x4 F250 w/6.7 PSD, bone stock. I do not know his gear ratio, size of fuel tank, or the speed at which he ordinarily tows. However, he claims 16 MPG towing in and around FL and GA. He is a VERY trustworthy person and has ZERO ego. I do not doubt for one second what he has told me.

Might be a trustworthy guy but he's sadly mistaken (or just really bad at math) if he really believes he's getting 16MPG towing a 10k lb 5er.

I've known him most of my life, and there's hardly anyone I would ever trust more to be truthful to me (and everyone else). He says it, I believe it. Hunt around the internet and you'll find other people with similar claims. Keep in mind that many of the roads he would travel to the campgrounds they frequent are flat highways without stop/go traffic, and where the speed limit is often limited to 60 MPH or less.

Like I said I'm not questioning his integrity, just saying he's sadly mistaken if that's what he's claiming as his "average". Your choice if you wish to believe the numbers. And yes, there are lots of "claims" out there as you put it on the internet. Imagine that...

4x4ord wrote:

My numbers would be reflective of about 65 mph both towing and non towing. At 80 mph 15 sounds about right....I think when I am conscious of my fuel economy I tend to drive slower, so, as a rule, if I am driving 80 mph I don't pay attention to my mileage.

Ah that makes sense!

Lines up perfectly with what I would expect. A lot of people post their MPG numbers without relevant details like speed or towing.

So it's hard to take the numbers at face value.

Thanks for your input! :)

crshman wrote:

4x4ord wrote:
My '11 with 20" wheels gets about 17 miles/US gal non towing. This is based on a long enough trip to include a regen. Summer time I might get 19 mpg. Towing I get anywhere from 5 to 11 mpg depending on what I'm towing. 11 towing the Rv....about 23 - 24000 lbs gross combined weight.

How fast are you driving loaded and unloaded to get those numbers?

I calculated FishOnOne's average speed to be 55 mph from his picture.

I drive my '14 F250 6.7 with a lead foot around 80 mph and I see 15mpg on average.

My numbers would be reflective of about 65 mph both towing and non towing. At 80 mph 15 sounds about right....I think when I am conscious of my fuel economy I tend to drive slower, so, as a rule, if I am driving 80 mph I don't pay attention to my mileage.