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Discussion Starter #1
My mileage started out looking really good. I got 21.7 hand-calculated driving 65 on cruise control at 3000 miles. I thought this was awesome. But subsequent checks (hand calculated) kept showing the mpg dropping with more accumulated miles. Mileage had dropped to 18.4 at 65 mph on cruise at 10500 miles and using Cetane booster also. I just changed tires from 265/70/17 stock to 285/70/17 running 80 psi. These tires are 1 inch taller and 3/4 inch wider. Not a huge increase in size at all. However I lost 5.5 mpg at 65!!! Evidently it really does make a difference when the computer is not updated as to a change in tire size. I am going to get that done tomorrow. I am seriously thinking about getting rid of this truck. With diesel prices ramping up with no end in sight and my mileage falling off a cliff, I think I will lose this truck before it gets any more miles on it. I would definitely not recommend anyone buy one of these new ford trucks.
 

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nice way to fly off the handle :roflol: chances are you rarely had regens early on and resulted in great mileage. As the DPF got a little older you are probally regenerating more often.
1" taller and 3/4" wider makes a huge impact on mpg, plus you're registering less miles than actually driven with a larger diameter. To not recommend your truck solely on mpg is pretty sad, especially after reading your older post where you praised the reliability and creature comforts. Plus, name a manufacture who gets better mpg? They are all within 1-2 mpg of each other.
 

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My mileage started out looking really good. I got 21.7 hand-calculated driving 65 on cruise control at 3000 miles. I thought this was awesome. But subsequent checks (hand calculated) kept showing the mpg dropping with more accumulated miles. Mileage had dropped to 18.4 at 65 mph on cruise at 10500 miles and using Cetane booster also. I just changed tires from 265/70/17 stock to 285/70/17 running 80 psi. These tires are 1 inch taller and 3/4 inch wider. Not a huge increase in size at all. However I lost 5.5 mpg at 65!!! Evidently it really does make a difference when the computer is not updated as to a change in tire size. I am going to get that done tomorrow. I am seriously thinking about getting rid of this truck. With diesel prices ramping up with no end in sight and my mileage falling off a cliff, I think I will lose this truck before it gets any more miles on it. I would definitely not recommend anyone buy one of these new ford trucks.
PM me some details on your truck...I may be interested in "taking it off your hands!"
 

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Discussion Starter #4
My truck is a crew cab / short bed XLT. Silver. Brand new bf goodrich 285/70/17 tires put on yesterday. Installed a ranch hand front bumper replacement. Extreme spray-in bedliner. 11450 miles. Truck runs great but mileage is steadily getting worse. Taking it to a Ford dealer in Houston tomorrow to try to find out what is happening. I don't think a tire size 1 inch taller and 3/4 inch wider is a huge difference but maybe it is and especially if the computer does not know the revs per mile has changed. Running 80 psi in tires. Truck is absolutely stock other than above-mentioned mods. I had a nagging feeling when I bought it that I should not have bought a first-year truck release to make sure all the bugs were worked out. Hopefully a dealer can help resolve the loss in fuel mileage. I have been running some cetane booster in an effort to stop the declining mileage but that didn't help. Weather has not been real cold in south Texas to have the diesel seasonal change so cannot attribute it to that either. Will post what the dealer tells me about what the problem could be.
 

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Discussion Starter #5
Re-gens actually became fewer in number as truck accumulated more miles. I am thinking possibly I could have gotten some dirty diesel at some time and the fuel filter may be plugging up. Just a guess. After hearing all the horror stories about the 6.0 and the 6.4's I am gunshy about these new drivetrains but hopefully Ford has gotten these right. The truck is a dream to drive but I don't want to end up with a truck that gets 4 mpg and diesel is at 6 or 7 dollars a gallon? Don't think it can't happen.
 

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Discussion Starter #6
I am not above getting a tuner and deleting ALL of the emissions junk if that is what it takes to make this truck run right.
 

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Re-gens actually became fewer in number as truck accumulated more miles. I am thinking possibly I could have gotten some dirty diesel at some time and the fuel filter may be plugging up. Just a guess. .

That is actually a good place to start (fuel filters). I can't remember how many post I've seen where folks say that fuel filters fixed their woe's. Plus a $100 filter change (which you're due for soon anyway) is a lot cheaper than taking a hit on selling the truck.
 

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This has to be a joke. 18.4mpg and your complaining. The best I have gotten is 18.1mpg. I think you should have bought a VW Jetta TDI instead of a 8,000 pound brick if you wanted good mpg. What would you do if you were getting 13mpg like I am in PA running winter blend fuel. That's running empty and not hauling anything.
 

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Discussion Starter #9
Not getting 18.4 with the new tires. I am getting 13.5 and that is not acceptable. Just got an oil change Saturday but recommended interval for the fuel filter is at 15k. I don't know if they can look at the differential pressure across the fuel filter while hooked up to reprogram tire size and revs per mile for the new tires. I really like this truck but I will not put up with any problems like this if they persist. If necessary I will go back with original size tires. I could well expect this if I went to say 35's but I just went a tenth less than an inch taller and almost .75 inches wider. That is not a huge difference in tire size. And maybe setting the computer for new tire size will fix it completely. I don't feel any real difference at all in the way the truck runs with the slightly larger tires. It will bust 'em loose at will and accelerates just the same. I am getting much closer to purchasing a tuner and deleting all the emissions stuff. Unless I just get a pre-2000 model ford and put a cummins in it. I believe this new engine has tons of potential in it just choked with all this emissions equipment. But the truck itself is incredible; and if it got 18 mpg consistently (not towing) I am OK with that. I am not OK with 13.5 mpg not towing anything and driving very conservatively. There has to be a problem for it to be doing that.
 

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I know for a fact all of our odometers are off on the 2011 even in stock form as much as 3%. I went from 33's to 35" Nitto Trail Grapplers and lost at least 2-3 mpg if not more but I knew this. My odometer is also now off 7.8%. If you do the math I should only be off 5.6% so I'm assuming that I was off over 2% stock. Once you check it and add the extra mileage I think you will find that you didn't lose as much as you thought. The computer calculated mileage my truck displays now is just about dead on to hand calculated mileage. And now that the winter fuel is here I have also lost another 1.5-2 mpg. I can consistantly get 16 mpg on the highway with my setup but not in the winter. Just my .02!
 
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Ive got a 2009 f350 dually with 4.30's and get 10.2 empty. I dont know why people buy big trucks and then ***** about mileage? If your not hauling a lot or not using a truck for what a truck should be used for then dont buy it. Its a truck and 14 mpg is still good.
 

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Discussion Starter #12
I had two dodge trucks with the cummins 5.9b engine and they both would regularly get right around 19 to 20 mpg. Plus I could tow with them and I think these new Ford trucks should be capable of delivering at least 18 mpg consistently with the available 3.31 and 3.55 axle ratios. Just got the computer set for the new size tires so will monitor the mileage etc. Evidently I am the only ford truck owner who cares about fuel mileage and I still think these trucks should do considerably better than 13 mpg. I have a neighbor who has a 1999 F250 with 534000 miles (claimed) and he says he has always gotten at least 17 and usually near 20 when not towing. Just seems like these new trucks should perform similarly to me. Another guy I know has a 2007 with a egr-deleted 6.0 and he is getting 18 plus consistently. So when diesel costs 6 dollars a gallon maybe some here will care about mileage a little more?
 

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southern-stroke
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227 Posts
You also mentioned you had a ranch hand replacement bumper... Umm, those things weigh alot. Like 500-600 lbs. And that'll make a difference in milage. Plus bigger tires. Plus any weigh in the cab or bed.
 

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Tyler
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thats really not bad mileage compared to the 6.4liters. they get like 8-10. id be b****ing about that but not 14-18. plus with all this added exhaust backpressure over the 6.4s exhaust system its still way better. i think the ford 6.7 is a huge improvement over internationals 6.4 but i still love my 6.0
 

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My bone stock 11 550 is getting similar mileage to my 08 dodge 5500, with no filter or egr. Both have 4.88 gears, flatbeds and weigh just over 13,000.
With oil pushing 90 bucks, my tickets get signed with a smile and they never even look at the amount. Hate to see what I could charge if fuel hit six bucks, but its nice to think about it.
 

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Discussion Starter #16
I think the 6.7 has a lot more potential than a lot of people realize. Over time the new drivetrain will prove itself. Just wish it was legal to run without all the emissions stuff. The loss of mileage is symptomatic of the engine being choked down and that in a nutshell is what bugs me about all these new trucks is mandated emissions stuff.
 

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Not getting 18.4 with the new tires. I am getting 13.5 and that is not acceptable. Just got an oil change Saturday but recommended interval for the fuel filter is at 15k. I don't know if they can look at the differential pressure across the fuel filter while hooked up to reprogram tire size and revs per mile for the new tires. I really like this truck but I will not put up with any problems like this if they persist. If necessary I will go back with original size tires. I could well expect this if I went to say 35's but I just went a tenth less than an inch taller and almost .75 inches wider. That is not a huge difference in tire size. And maybe setting the computer for new tire size will fix it completely. I don't feel any real difference at all in the way the truck runs with the slightly larger tires. It will bust 'em loose at will and accelerates just the same. I am getting much closer to purchasing a tuner and deleting all the emissions stuff. Unless I just get a pre-2000 model ford and put a cummins in it. I believe this new engine has tons of potential in it just choked with all this emissions equipment. But the truck itself is incredible; and if it got 18 mpg consistently (not towing) I am OK with that. I am not OK with 13.5 mpg not towing anything and driving very conservatively. There has to be a problem for it to be doing that.

First of all..the truck..{she} knows you are upset with her.. Start talking nice to her, building up her self esteem..and watch what happens..




I changed tires to 325 60 r20's on my 350..my mileage dropped also..take it in, explain the situation..and if not, sell the tires and put the stock ones back on...but then go back to the dealership and have it run through the computer again.. Good Luck..Getting a 1/2 ton..like I also have will not really yield any better mileage..and if you go to another brand they are the same..
 

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Ford the best

My mileage started out looking really good. I got 21.7 hand-calculated driving 65 on cruise control at 3000 miles. I thought this was awesome. But subsequent checks (hand calculated) kept showing the mpg dropping with more accumulated miles. Mileage had dropped to 18.4 at 65 mph on cruise at 10500 miles and using Cetane booster also. I just changed tires from 265/70/17 stock to 285/70/17 running 80 psi. These tires are 1 inch taller and 3/4 inch wider. Not a huge increase in size at all. However I lost 5.5 mpg at 65!!! Evidently it really does make a difference when the computer is not updated as to a change in tire size. I am going to get that done tomorrow. I am seriously thinking about getting rid of this truck. With diesel prices ramping up with no end in sight and my mileage falling off a cliff, I think I will lose this truck before it gets any more miles on it. I would definitely not recommend anyone buy one of these new ford trucks.
=======================================

You guys buy a beautiful new truck and start changing what taken Ford Engineers months to figure out to give you the best gas mileage and then complain about it! I have a 2011 F-250 Crew Cab Short Box 4X2 with a 3.31 rear-end and I get 18-19.5 MPG around town and have gotten 24.9 MPG at 55-60 mph.. My town driving is lite.. Most of the time I drive between 60-70 mph and get 21-22 MPG.. I now have 6650 miles on my truck and she just keeps getting better with age.
Thanks:usflag
 

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Senior Member
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I had two dodge trucks with the cummins 5.9b engine and they both would regularly get right around 19 to 20 mpg. Plus I could tow with them and I think these new Ford trucks should be capable of delivering at least 18 mpg consistently with the available 3.31 and 3.55 axle ratios. Just got the computer set for the new size tires so will monitor the mileage etc. Evidently I am the only ford truck owner who cares about fuel mileage and I still think these trucks should do considerably better than 13 mpg. I have a neighbor who has a 1999 F250 with 534000 miles (claimed) and he says he has always gotten at least 17 and usually near 20 when not towing. Just seems like these new trucks should perform similarly to me. Another guy I know has a 2007 with a egr-deleted 6.0 and he is getting 18 plus consistently. So when diesel costs 6 dollars a gallon maybe some here will care about mileage a little more?



Compare apples to apples dude. That 5.9 is a dinosaur compared to a 2011 and what the Gov. is making the big three do to the trucks today.
 

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Member
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My mileage started out looking really good. I got 21.7 hand-calculated driving 65 on cruise control at 3000 miles. I thought this was awesome. But subsequent checks (hand calculated) kept showing the mpg dropping with more accumulated miles. Mileage had dropped to 18.4 at 65 mph on cruise at 10500 miles and using Cetane booster also. I just changed tires from 265/70/17 stock to 285/70/17 running 80 psi. These tires are 1 inch taller and 3/4 inch wider. Not a huge increase in size at all. However I lost 5.5 mpg at 65!!! Evidently it really does make a difference when the computer is not updated as to a change in tire size. I am going to get that done tomorrow. I am seriously thinking about getting rid of this truck. With diesel prices ramping up with no end in sight and my mileage falling off a cliff, I think I will lose this truck before it gets any more miles on it. I would definitely not recommend anyone buy one of these new ford trucks.
Since you haven't given us any Service History, I'm wondering if you've taken your truck in to the Dealer to have them check it out?

My guess is that it is something more than a tire change which calculates to less than a 4% of your mileage loss because your odometer is showing less miles than what you are actually driving.

Taller tires means "higher truck" which means "more drag".

Also, I've run every brand of Cetane additive and have found that many have hurt my fuel mileage, in particular the stuff that Walmart sells (can't recall the name but it is the most commonly used additive). Most of these additives are Snake Oil!

Just because you live in Houston doesn't mean that you are getting Summer Fuel. Winter fuel can cost you 10% in fuel mileage.

Were all of your mileage "test" on the same road, came outside temperature, same traffic, same wind & direction, etc.?

I drive from Lubbock to Tyler all the time and have seen as much as 4 mpg difference, due to the above mentioned factors.

Lastly, where were you when we were all paying $4.00 a gallon for diesel with some of the unfortunate folks in California paying nearly $6.00?!?!?!?! Did you really think it was going to get down to $2.00 and never go back up again?
 
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