Since day one, (last October) bought with 528 miles. our overhead computer has never read more than 14.8 mpg. That was the first 2 weeks we had it. We have been told time and time again you will see it jump when you get above 15k or more. Well we are now at 24k, it has not been in the 14 mpg in 6+ months. Everytime we get diesel and there is another Ford 350 fueling up I ask what their computer is showing. You guessed it, virtually everytime I have looked in the cab it is 15, 16, 17 and as high as 18.3mpg. Recently a gentleman told me the only time he is down where I am is when he is towing his travel trailer. Took it into Ford, they said dyno is reading 17-18 mpg. They said they will have to reset the overhead. Got it back, filled up, 698 miles to empty which is on target, switched over to mpg, 13.3. Does anyone know what is wrong because the techs at the dealership don't? Further, when we fill up, I make sure it is topped off when doing so that thing is between 450 to empty, up to what is was last week after leaving the dealer 698, and that is the highest reading ever.


Also slight vibration side to side randomly while on highway. Ford says nothing is wrong, it did not ever do that in the first 20k, that steering wheel did not move.


Thanks in advance for any suggestions.http://www.dieselplace.com/forum/smileys/smiley5.gif

got me on that one. Do you have a steering shock? And, what do you hand cal the MPG to be?


Just guessing.... the pedal position may have somehting wrong with it? It's either that or a fautly wire....don't know.





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if i did not know better i would have thought you have stolen my truck. since day 1 i have gotten 14 mpg with my f350 4x4. i dont' have the computer but i measure and record every tenth of a gallon that goes into the truck. i fill to the top and then check mileage. i know have 12k miles and still get the same mileage. i have even improved the air intake and exhaust and still no mileage improvements. it sure does run well though. i also have the vibration as you mentioned. i cannot get back to my dealer but he thinks that it is a defective drive shaft. he has seen that. i have asked dealer here and they say there is nothing wrong. i have even tried code changes to improve horse power but now mileage increase. it is very discouraging. when i tow a heavy load mileage drops to a consistent 10 mpg.


tom

If you want that good mileage, keep rpm's under 2k. i can get 20 mpg hwy if i keep it at 1800. bump it up to 2000, get 16 mpg. 2200, only get 14 mpg. Also depends on how fast you go from a stop. keep it below 2k, feels like grandpa is driving, but you get great fuel economy. So many people upgrade hp with aftermarket eqpt and want to see better mpg, well who can resist using that hp? It's a very easy equation. take it easy = +++ mpg....put your foot in it = ---mpg

Well everyone, I appreciate your assistance, I have posted on several other forums as well. It is definitely the thing to do with vehicles like ours. The knowledege out there is tremendous, it is baffling to me how everyone knows more than the damn mechanics at the dealers.


So I told them what I have got back on the different forums, they reset everything, took the truck up north, bang, 17.6, 17.9, 18.5, It was great watching the computer because it stayed the same for so many miles. Re-fill, reset, drive a little slower, I am thinking cmon you can reach 19. Sure enough, coming back on I-75 driving with cruise control on at 72 hit 19.7. They had to disconnect the battery to reset everything.


We still have the steering wheel shake issue, so it is going back in next week for that. They claim they had the tech, and the shop manager both drive it and both say it is fine. Yet, we drove some 500 miles and as soon as we hit 50+ it started like clock work. Nothing crazy just a slight back and forth movement. One forum said they have had issues with steering columns on 03 and 04's.


Thanks again everyone!