ODD Mileage Dillema..............

[chach3835]

First off 99 May of 99 truck F250 4x4 CC SRW Auto 7.3 PSD stock except DIY cold air intake Napa filter 6637. 210k


Ok guys I was heading out to Pittsburg this past weekend. I live just outside of Toledo and was taking the turnpike and the winding roads out to Burggetstown PA. I filled up @ home and got just outside of Cleveland and decided to fill up I had just over 1/2 of tank and to my shock I checked my mileage I was getting 11 MPG. WHAT THE HELL......I was using the cruise the whole time and up to this point it was not really hilly. I then decided to quit using the Cruise, and then got into the hills and mountains the checked my mileage and guess what I was getting 17MPG. I got to the place and had filled up twice both times there was just over half a tank left. I then came home on Sunday on one tank of diesel and have between 1/4 and 1/2 a tank and have not checked the milage but its looking good. Ok guys what gives about the 11MPG that is just crazy.......the only thing I did different was the cruise does this really make a difference in a diesel truck? I have no major mods I only have DIY cold air intake. Every thing else is stock. What is your guy's guesses

 

[li'l tugger]

my guess would be crappy fuel at the first fill up? i have had 3-5 mpg difference between fuel stops on flat land with the cruise set. or maybe you were driving against the rotation of the earth for the first tank if you went up to 17 mpg on the second fill up, then up a little more once you got back on the highway on tank 3 or 4.. i would say bad fuel was the culprit.

 

[argve]

yep I'm going to say that she didn't like the fuel. There has been a few times that I have gotten fuel that didn't quite agree with my trucks stomach and left her a little green around the mirrors but a couple of tanks later and the mileage was back up.

 

[chach3835]

If that is the case, I will not be getting diesel from that gas station back home. WOW that was some crappy mileage.

 

[res0wc18]

uh well that is what i get in my truck no matter what i do... it makes me mad this thing is a regular cab and should be getting 18 or better no matter what.. So i am a loss for words... no idea why this damn thing gets such HORRIBLE fuel mileage...


I would say that there is something else going on... My truck is one of the healthiest i have seen.. it should not get this crappy mileage...

I have tried addtives etc etc slight change... something has to be wrong... could the computer need to be reflashed because its running too lean with the tymar full exhaust and banks full kit?

What the heck? i feel youre pain.. its pathetic

 

[li'l tugger]

i've heard something about a bad injection computer bringing mileage down. i only get about 13.5 to 15 no matter what i do but i have an early 99 so that may be my problem. i wouldn't worry too much if it just happened once. just avoid that fillin station

 

[res0wc18]

My mileage has always been terrible no matter what station i get it from..

 

[chach3835]

I checked it today from my trip on Sunday one tank and got 19.5 mpg....WOW a lot better and could have gotten better if the mountains did not get me on the up. I will check here out some and see if I do better, and yep going to stay away from the diesel @ that station, just filled up today at the one close to my house.

 

[res0wc18]

yeah see.

Here is the situation

97 f350 reg cab stroker 4x4 e4od. Full banks kits diy tymar full turbo back 3.0 to 4.0 inch etc etc 4.10 gears 35's


No matter what i do this thing will not break 13 mpg! What gives? This has been bothering me for quite some time now...

What can i check/ do?

If your crew cab gets that my reg cab should get better!

If my truck still has all the stock computer settings would that cause it to get really bad mileage like it was running too lean or something? I have know idea how to tell if it has been chipped or reflashed etc etc?

The trucks seems to run/ sound good it just gets horrible mileage?

 

[li'l tugger]

resowc18.. your mileage may be due to the gears and 35s. did yu have the truck before the gears and tires? my 95 4X4 gets about 17mpg on 37s but it has stock gears. do you blow any smoke when punch the throttle? if so, you're not lean fo sho.

 

[NCheek]

There is no such thing as lean/ rich fueling on a diesel, there is no throttle in the intake. Engine speed is controlled by fuel, and therefore, there is an infinitely variable fuel/air ratio. If you want good mileage, your going to have to baby it all of the time. 4x4 and large tires doesn't do well for mileage either...

 

[res0wc18]

4.10 stock gears.... same tires that came with it.. no smoke ever...

I dont get why my 67 kaiser duece gets the same mileage as this...

From what i have been told this is not normal.. i have a friend that has a crew cab with 4.10s 35s etc etc and he has twice the mileage on his engine and gets 17.6 mpg avg?

I have no idea what gives.. i hate to say it but if i dont get this figured out i am going back to a CUMMINS aahahah

 

[NCheek]

Are your gears 3.55's or 4.10's? Winter fuel vs. summer fuel?

 

[res0wc18]

4.10 gears oops

fuel ill have to check.. but i run offroad... oops

 

[NCheek]

I'm no powerchoke expert, but it might not like the fuel... When was the last time you changed you fuel filter? Might want to do some religious testing with additives to see if that helps. If it turns out to be winter fuel, then that is most likely your poor mileage issue.