Ford fuel mileage

**piper guy** · 12-22-2014, 06:40 PM

Ok, this is sure to be a hot topic but I figured it was time to open a can of worms ....

For those of you with 2012 or newer F350 Dually's , I'd be curious to know what speeds and mpg you get. I've now towed my 36RL about 15,000 miles total. Have been in all kinds of terrain other than the western mountains (hopefully this summer for that ).

In my truck with the 3.73 gears and in regular conditions, ie rolling hills , mostly semi flat, no mountains, I get a consistent 10.3 -10.5 mpg when running 68 mph. I find in mine, if I run slower, say 62-63, I actually lose about .4 mpg. If I run 70, doesn't seem to change any.

I haven't tried going considerably slower as here in the North East you would get run over and off the road by Semis. If you don't run with the traffic you literally take your life in your hands.....

As the saying goes, your mileage may vary, but I'm curious what the others are seeing.

atom ant · 12-22-2014, 06:45 PM

Vaughan - you mean towing, correct?

0nTheRoad · 12-22-2014, 06:58 PM

This year we've logged about 8,000 miles towing, I typically drive at about ~65mph, really focus more on the tack and keep it at ~1,700rpm and we're averaging 10.2 mpg. I'll experiment at a little faster speed to see what happens over the next couple of months.

johnboytoo · 12-22-2014, 07:07 PM

SO many variables for mpg...

How much wind, how hard you accelerate and decelerate, the grades you go on, wheel alignments, bearings, are brakes dragging?, tire psi, etc....

My fall back on the mpg question of want a big truck and want to pull an rv?

get a vehicle that will do it and the mpg is what it is

**Dave&Ginny** · 12-22-2014, 08:15 PM

Quality of fuel makes a big difference on the diesels as well as the wind. The sweet spot on my truck seems to be around 1800 RPM with 373 rears.

With that said, I always weigh in my head what time I have to get somewhere and how much that 1.5 mpg is really costing me if I go that extra 5 per hour.

**Blenhardt** · 12-22-2014, 08:24 PM

I don't fall into your 2012 or above classification but with my 2011 6.7 engine I have averaged right at 11.2 over about 30k miles. Depending on wind, hills, and traffic as low as 8.5 and as high as 13. Also a 3.73 rear end.

spindrift · 12-22-2014, 09:19 PM

I'll keep it simple...11mpg for me.

0nTheRoad · 12-22-2014, 09:28 PM

So what are you guys doing to get over 11mpg, how fast do you drive, which differential do you have, any mods to your trucks?

spindrift · 12-22-2014, 09:54 PM

I'm sure if I slowed down, I'd do better than 11mpg it's just that the truck wants to run at least 70mph.

CV67Cheng · 12-22-2014, 10:23 PM

Vaughan, with 31SL in tow, weighing in at 14,760, 23,865 gross 3:73 gears, my computer states 9.8 - 10.4, I drive 65-70 all over VA including areas west of Afton Mtn. Empty I average 15.3-16.8.
Bob

**piper guy** · 12-22-2014, 11:47 PM

Brad - yes, towing. Forgot to mention that. Just the truck running around, usually 15.5-16.5 or so.
I was just curious how others were doing as in the past I have held around 1800 rpm but on the last trip was up closer to 2000 to keep running with traffic and the truck and rig actually seemed happier there and mpg didn't suffer.

Bruce, my apologies, I forgot there are some '11 trucks with the 6.7

**Blenhardt** · 12-23-2014, 12:11 AM

Vaughan, No problem. Were there any 2011's without the 6.7?

Forgot to provide my driving habits. I try to drive from 62 to 66 mph. Seems to me that the truck likes that range best.

spindrift · 12-23-2014, 12:17 AM

Quote:

Originally Posted by Blenhardt

Vaughan, No problem. Were there any 2011's without the 6.7?

No...we're not talking 6.0L here.

mhs4771 · 12-23-2014, 12:49 AM

I don't know what you Guys are doing wrong, there's a post over on RV net about getting 18 plus towing a good size Toy Hauler with a 2003 Ram and 5.9 Cummins.
Sorry, the Bow Tie made me post that.

spindrift · 12-23-2014, 12:51 AM

You mean a Cummings, right?

mhs4771 · 12-23-2014, 12:54 AM

Yea, spelling was never my best,
Just thought I'd throw it in to stir the pot a little.

mhs4771 · 12-23-2014, 01:08 AM

Guess maybe I was correct to begin with: Cummins Diesel Specs | 5.9L & 6.7L Cummins Specs
Either way, we all know what it meant, at least I hope we do.

**Dave&Ginny** · 12-23-2014, 01:29 AM

If it's on a forum it must be true

atom ant · 12-23-2014, 02:45 AM

I'm about 16.5 running 75 mph and am set up identical to your Vaughan. I can't say towing, as I haven't played enough. I only really have 2,500 miles on it so far, so not really past the break in stage yet.

The 3.73 and maybe some other contributions of transmission and engine and really improved my mileage. The 6.4 with 4.10s pretty much slipped into 8 or 9 towing.

lwg · 12-23-2014, 03:28 AM

While I don't have a dually I do have a Ford 6.7 with 3.73 rear end. I rarely get over 10 MPG towing, ever. I usually can squeeze out that good of mileage for short durations but it doesn't hold. I've just started using 9.5 MPG for my cost calculator. Keep in mind this is completely travelling in the west though.

Also, I've noticed on the Ford forums that no two Ford's get consistent mileage. Seems like programming, break in, fuel and other things factor in a lot with this engine.

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