I don't think SC does the diesel winter blend like the northern states. I'm pretty sure NC doesn't either. I've been wrong before, so take that for what you paid for it. Your mileage seems on the low end. Do you have a pic of your truck? How wide are your tires? Width could play a fairly large role in mpg.

When I shut my truck off during regen I can hear the exhaust metal ping and pop like hot metal does. Not only does it stink, but it's noisy too. Are you hearing that?

Wasn't there one guy on the forum that was leaking DEF into the exhaust causing some bad mpg? That would smell weird too.

 

They are supposed to be 35x12.50r20. But I'm measuring about 33.5x11.5 on them. Yea if I shut down in regen I can hear the pipes ping.

 

oh good Lord dude, your mileage looks about right lol.

 

Lol ok! Just making sure I'm not crazy. I was pulling about 12.5 mpg around town on a 06 f250 with 37's. And was seeing about 17-18 on the highway. And maintaining about 12 towing the boat in the background. I just about cried when I towed with this one the first time and saw 9.8 mpg. Granted I didn't even know the boat was behind me

 

That sir is a beautiful truck!
Merry Christmas!

 

Nice looking truck!!! But....... with a duallie on tires like that, it propably is right where it is going to be for fuel cunsumption. I get around 14 overall when not towing,(highway, town, including regen) with mine on stock rubber. My lifetime average(just under 18,000 mi) is right at 11 MPG, and that includes around 7000 toiwing my Raptor, 2000 towing the 38' enclosed gooseneck, and 2000 pulling the 18'flatbed for a total of 11,000 miles pulling

 

Well, I was off today. Ended up under the truck and think I found my issue. Atleast on the regen smell. The exhaust has come looze! It's behind the last canister about where the cab and bed meets. I had a three inch gap and the exhaust pipe over the axle and out the back of the truck is wobbly! Somehow or another, the three bolts on the flange have either rusted or sheared off! I was coming up on a regen so we c-clamped it back together tonight because we couldn't get the welded studs out. Guess I'll be calling the stealership in the morning. I "hope" this will be a warranty item, but I'm not betting on it. I know I haven't done/hit anything that could have caused it, but can't prove that to them. Truck is a 2013 w/77k on it. I haven't found a clear answer, do I have any factory warranty left? They gave me a 4yr extended when I bought it. I've about made my mind up that I'm not dumping a penny of my money into this boat anchor exhaust. But I recon I'll cross that bridge tomorrow after talking to the dealership

 

My 2016 F-350 6.7L w/ 3.55 on stock 18" tires achieved excellent mpg - as high as 26mpg unloaded over 100 miles, no regen, and a lifetime average of 16.5mpg including a fair amount of towing, city driving, idling, and winter 4x4 use.

My 2016 F-250 6.7L w/ 3.55 on 35x12.5x18 BFG KO2 tires took a severe mpg hit because of the tires - that same 100mpg route was now 20mpg, no regen, and lifetime average was at 15mpg with not much towing.

My current 2017 F-350 dually has the 3.55 gears as well, on stock 17" tires, 6.7L, can achieve 20mpg, no regen, on that same 100-mile route and has a lifetime of 14.4mpg with a fair amount of towing and some (so far) winter 4x4 use.

Those look like 35" tires to me. The aggressive treads, the width, and the dually rears will easily net you poor mpg like that.

Truck looks awesome, by the way.

 

Update to my original post. Didn't want to start a new thread. The trucks mileage still seems to be going down. turned on my obdII yesterday, and saw that I was at 95% soot, Had nothing to do, so I figured id run it down the interstate and let it clean. was approaching 98% when I hit the interstate, and thought finally, I timed it right. Well, 10 miles down the interstate, no regen. Got back down to 86%. Drove back across town to home, goes into regen pulling in the driveway!! Went in and ate dinner, came back out, truck had cooled down. Drove and Drove last night to finally get it to complete. Probably about 20 miles before it finally kicked in. Regen brought it down to 16% soot. was back up to 23% today after driving about 8 miles. Mileage since last regen was at 418 last night when it started. She started throwing a P20ba code about 2 months ago, mysteriously went away for over a month on its own, added two gallons of DEF Friday, now the light is back on!!! I'm about fed up with this boat anchor system under this truck! Truck is now down to average of 10.6mpg. Yes, I do drive a lot of short 5-8 mile trips around town, but I always drive until a regen is complete when my light comes on. Any ideas on what to do? I was on the phone With Rudy's diesel discussing a possible solution to my issues today. Downside is I still have a Yr warranty left from Ford, just doesn't cover the emissions.

 

Are you using a scanner to get those readings, or did you enable it for the dash readout? Mine's on the dash but it only moves in 5% increments.

My regen takes about 4.5 miles after it says exhaust filter full before it starts up.

 

mine is on a Torque pro scanner. all I see is percentage. and a very quick "cleaning exhaust filter" message that flashes so quick I barely catch it. When I look on my scanner, I have a nice green light that comes on during regen and stays on until its done. miles during regen last night were about 8-10 miles.

 

Rudy's does have some very nice ways of dealing with emission system issues.

 

If you have a CEL or code take it to the dealer and get it fixed while it's under warranty. At that time I would discuss the fuel mileage concern.

 

Unloaded we get 15.7 and 10 towing our rig at speed limit all stock with 30K
I agree could be the tires..did you get speedometer adjusted for tire size?
Is the smell..rotten eggs....def is working

 

I agree, I'm sure these tires are throwing my mileage off. The speedo is calibrated to the best it can be I believe. Tires "say" they are 35's but measure out to about 33 1/2/ in tall. Truck was set up this way when I bought it so idk what it was getting before the tires and leveling kit. The smell that I was speaking of earlier on in the post is now gone. It smelled like it was in regen all the time. The culprit for that best I can tell was the three bolts that sheared off on the exhaust at the back of the cab/under the bed. I had a three inch gap that was letting exhaust come out under the truck.




The remaining warranty that I have is the powertrain, which, I have been told doesn't cover the emissions parts. I still hate to loose the remaining powertrain on the motor/trans because a LOT can happen in a years time. I'm just really trying to weigh out spending 200-400 dollars to fix my check engine light, which is coming from the def tank heater according to the code to keep a year worth of warranty when that would go a long way on the delete. I've already planned to delete once warranty is out. I'm just torn whether or not I should do it now or wait. I can clear my check engine light but it's getting aggravating doing it every day. Yesterday, when the check engine light came on, the truck felt like it shuttered a little bit