Hello everybody, very new in this post...
I actually have little problem I never can get more then 12 mpg on my power stoke.
Last week i changed to N&K filter inflated my tires and went camping and surprise 11mpg.
I don't really know where to start but.. I'm envious of those bragging guys of over 20mpg.
I drive bit over 75, have a ladder rack with 2 ladders on it, pretty stock...
any advice? Thanks all, Marek

 

My question is....who the hell buys a 7 or 8 thousand pound TRUCK, and then decides to start worrying about fuel economy ? I just don't get it, my 99.5 cc,4x4, dually gets a respectable 20ish empty, under 2k rpm, and I'm damn happy with that, and when needed....mashing the skinny pedal provides plenty of extra oomph, keep the rpms down, or buy a prius.

 

Wow, lots to cover in this thread. Speaking as a Mechanical Design Engineer I can tell all of you engineers don't make the critical calls when it comes to design. They may propose a design, which is likely a very good design, but as soon as the financial guys, manufacturing guys, and marketing guys get hold of it things change drastically.

OEM designs will always be comprised of compromises based on cost, ability to manufacturer, and marketing strategy, not to mention government regulations.

For thise who say OEM design is as good as it could be, you need to do some research. Any automotive engineer working for an OE would tell you they are forced to compromise their ideal designs for a variety of reasons, which means there is plenty of room to improve on the design. An OEM can not put straight pipes on a truck thanks to Uncle Sam, does that mean the truck won't be better off with them? No.

OEM designers are also required to design a truck for the general public, meaning they have to find a happy medium in their design that will make the most people relatively happy, not specific groups looking for mpg or payload or speed very happy.

As for mpg, I get 17-18 with 90% highway driving with cruise set at 70mph. That's with the mods listed in my sig. I almost always run in stock tune, but I'm currently trying my first complete tank on the 75hp setting to see if mpg goes up or down.

Lastly, for those out there that think OEMs can do no wrong and their designs are as good as it gets, tell that to the early 6.0 owners who have to spend thousands re-engineering their engines to not self destruct.

 

I have gotten 25mpg in my 03 F350 CrewCab empty. i drive like a grandpa though, towing my 68 Fastback i got 14 I am normally around 17-18 cause i mostly drive city.

 

Welcome to FTE!

Do you have the drop in K&N filter or the other one that replaces the whole filter box? The drops ins are known to leak and allow dust past the filter causing some very bad problems if let go for too long.

Driving at 75 will hurt your MPG, especially with a ladder rack and if you're towing a camper at the same time. The best MPG comes when you stay below 2000 RPM's. Some of the claims of 20+ MPG are from people who believe the overhead display. Its easily fooled by programmers and tuners into reading higher then what you're actually getting. The best way to calculate MPG is by hand.

EDIT: and holy old thread batman! 8 years and counting!

 

Hey I have a 99 f350 with a 7.3L diesel I'm getting terrible mileage to a tank of diesel like 238 miles I used to get around 325-375 don't have no smoke no fuel in fluids or oil no leaks in valley pan or under truck no symptoms at all of something wrong also changed air filter all the mods I have is DP tuner , K&N air filter tires are 325/75 R22 but have had everything the same for like 6yrs started bad mileage a year ago smh can't figure it out had it checked out at mechanic he says its no problem but something's wrong O also about 6 months ago I had a caliber sticking and didn't know till I did my tire rotation and wheel was locked thought that was my prob but it wasn't fixed it but same bad mileage please help any suggestions ??? Forgot to add I have 235000 miles on it tks

 

Ebp sensor cleaning and also the tube is a good cheap place to start. Also boost leaks will cause a loss in mpg

 

That's a lot of letters with no punctuation, yet there's a "." in 7.3 so you do know where the key is.

 

Twags6 I have the drop in filter and John2001 I did the EBP sensor change and cleaned the tube.'88 E-350 I'm no typist so if you want you can come behind me and correct the punctuations & even spell check if you would like ..... Happy now I put the .

 

Did you ever get your odometer set for your tire size?

Know anybody with a scan tool that can check your data while driving? There are links at the end of my signature that can help out.

 

Tugly no I didn't get it set but they've been on there like 4 years and problem started like 2 years ago but I dd swap tuners around that time and my super chip did have a tire size setting and the one I have now doesn't . Where would I need to get that done ? I'm guessing the dealership ?

 

Tugly would not having my speedometer calibrated to my bigger tire size make a BIG change in mileage of my truck ? I was getting 325-375 miles a tank to now maybe 235 miles ?

 

I'm not sure what the size difference is between your tires and stock. I can tell you from stock to 38s is a world of difference. With my 36s speedo uncalibrated the best I got was 16.16 mpg. 38s calibrated I get 14mpg consistently.

 

If I'm reading this correctly, you programmed your tire size into your Superchips and you got 325-375 miles per tank. You then changed to a different tuner 2 years ago and you started getting 235 miles to the tank at that time.

I suggest you first find somebody with AE or other scan tool and have your tire size dialed in. Take new economy measurements after that and you'll know what you really have to work with. You might have been getting the same economy all along, but in the process of pulling the Superchips... the tire size was altered at the time.

 

Ok thank everybody for all the responses tomorrow I'll take it to the dealership and see if they'll do it and I'll post the response after I get it calibrated and let y'all know if it helped �� it does this is really a headache almost makes me want to sell it but I love it so much lol but thanks everyone