Hey Folks.

Two quick questions:
What are you all getting for fuel mileage (and if you don't mind list any mods or over sized tires, chips etc that might effect it).

Secondly, my stock '96 f250 when I picked it up w/ about 155k on the clock was getting much closer to 18-22 miles per gallon depending on driving conditions. One day (i mean this did happen over time but much quicker than expected) I started getting worse mileage. I'm down to about 15 mpg mixed driving. I'm rather careful on takeoffs, its a stock setup, as far as I know the tranny has been rebuilt along the lines and feel pretty tight and the motor feels strong. Filters are pretty fresh, oil is topped off, tranny fluid is ok and I have even tried using Diesel Kleen, etc to see if that might help. I use it anyway but it doesn't make a difference mileage wise.

Does 15 mpg sounds right? How could I go from like 18-22 down to 15??? Even If i drive slower than the oldest old fart on the highway (55mph - and yes, I do drive that slow on a major highway in the right lane. ha-ha Hey trying to conserve fuel!!! LOL) it doesn't help enough.

Just trying to pin point some things to help with this $4.09/gallon fuel. I still get better mileage than my '84 f-150 302 gas truck but still i could afford a little better mileage. I know guy getting 22 regularly on their 7.3's

Thanks,
Al

 

Did you notice this drop off in the winter? I'm on my phone so I can't see where you're from but winter blend fuel will kill your mileage.

By "topped off" oil does that mean fresh diesel rated oil? How fresh are the filters? I do my fuel filter every 6k.

A bad MAP or clogged MAP line will hurt mileage as well. Make sure the line flows and isn't dry rotted. Unplug the MAP and of the truck runs better, but the line checks out, replace it. You will set a CEL, but this will go away when you plug it back in.

 

Honestly, The list of things that can hurt fuel mileage is an arm length long.

 

Right now the filters aren't fresh but i have getting this mileage since I put fresh filters in. Oil is diesel rated and synthetic. You don't think the synthetic is hurting it do you?

Where is the map sensor located? Had no idea our truck even had one. Ha!

I know it could be a mile long list as to where to start but figuratively speaking I feel as if the mileage went south overnight. I mean it didnt just creep down 1 mpg per year it went like 2 mpg over 6 months. I'm not certain on this figure hence why I say figuratively


Thanks

 

I saw a slight increase in MPG's when I switched to full syn. Were you running winter blend fuel? Like Talyn said, it's a long list to find the MPG gremlins.

Do a google image search for MAP sensor OBS powerstroke.

 

Mine is getting 11-12 consistently, but has been as low as 8.5

CCLB 4x4, 5 speed, 4.10 gear's, 35" tires, Tyrant tunes, Hypermax stage 1's, intake, exhaust

 

so I have 3" DP and the riffraff air filter kit... all else is stock. I get 15-16mpg...I'd love to get 18...

also note I have a 2wd supercab longbed.

Richard

 

The truck in my sig is getting hand calculated 18 at 65-70 mph with a bad alignment and broken ttb bracket. I ran out of diesel kleen two tanks ago and noticed a 1 mpg INCREASE with no change in habits. I spect it to go back to 19-20 when I get the front end straightened back out here soon.

 

I just did a mpg test last night on my 96 cclb 4x4 5speed with 3.54 gears. It has a custom 3 1/2in dp, no cat, high flow muffler, 6637 air, 265 75 16 all terrain tires and a brand new T500 and the rest is stock as far as i can tell. It has 276k on it and i calculated 18 mpg highway goin 65-70 with some hills involved using cruise. My 95 4x4 5speed eclb with a half loaded service bed gets 16 if i baby it with straight pipe, TS 6 pos, 6637 air, and 4.10 gears and 235 85 16 mud terrain. The 95 was getting 13 before the chip install so i am hoping to hit 20 with my 96 after chip install and straight 4in exhaust.

 

Yup. One thing you can do really quick is to make sure your tires are inflated to the specified pressure.

 

Alright I am going off topic, but Chase, would you rather have the 4.10s in your truck or the 3.55's with your ZF? I am contemplating changing to 3.55 gears. I am also considering a ZF swap, but with either auto or stick which would you rather have? My truck is my DD and it is usually empty, but I do tow and haul with it on occasion. Nothing really heavy, generally just up to the payload in the bed or towing 3-5k lbs. Very seldom if ever above 8k towing. I figured your truck would be a pretty close comparison to mine size and weight wise.

 

Oh and as an attempt to redeem myself from shamelessly derailing this thread, here is a recent thread in which the topic of fuel economy was covered extensively.

https://www.ford-trucks.com/forums/1...eage-tips.html

 

Hey i have the same exact truck as you, except I have the 5speed with 3.55 gears. I really like the setup, it seems to pull good, has a nice power band and runs at barely 2k at 65 much nicer than the 4.10's in my 95.

 

I get 8 or 9 pulling 16K 5er at 70mph (10 if I'm lucky) and light I'm usually at 14-15. A couple of weeks ago I got 17mpg and I about fell over at the pump. All I can say is I miscalculated. I've always have gotten lousy mileage, like Chase. My mpg has never changed no matter what mods I do. I know, I know, I have a lead foot pulling that 5er at 70mpg, I can't stand going slow. This is a hugh no-no but there are times I just let it roll down hill until I'm up to 80 and let it slow down on the up hill. My wife is usually reading a book or she would chew my a!! out.

 

Maybe worth asking: how are you computing MPG? No offense to anyone on the boards here, but some guys use...um..."scientifically questionable" methods. The only way to be accurate is to note your starting mileage with a full tank, then every time you fill up you add up all the total miles driven since the starting point and divide by the total of all the gallons pumped, keeping in mind that you still have odometer error to worry about with non-stock tires, etc. Using this method I see variations of 2-3 MPG from fill up to fill up- partly due to the differences in just how full I get the tank. But doing the long-term average minimizes the margin of error, giving you a more accurate MPG number.
I've put 8k miles on my '96 in the last 2 months running all over Los Angeles and Southern Cal, and my overall average is 19.8 (CCSB, 4X4, ZF5, 3.55)