In my area I've actually gotten a few tanks of bad gas from shell. Might just be coincidence but I use the BP gas now because of it. They cost me so much time and grief. I also use the Lucas fuel conditioner the week I do an oil change and it keeps my engine nice and clean. Not sure how using it every fill up would do on it.

 

durangom03 try a different gas station, it is possible that shell got some bad gas and it hasnt worked its way out of their tank yet,

 

Well first off are we talking about CORRECT mileage? People put non OEM tire sizes, rims, and other things on trucks. Second owners don't know of these changes.


First thing first! Ensure that you are actually traveling 1 mile and not other differences. You can do this with a GPS or simply using the highway markers. Highway markers are on the side of the road on a mounted sign. Simply push the reset button on the trip counter right as you pass it and check the mileage. When you get to the next one look at your mileage and check it to your findings. The further (mileage) you can go the better, for instance, if you travel 30 miles on the freeway then great, watch the highway markers and again refer to your mileage on your odometer.

Next lets start documenting the actual gallons used and divide by actual mileage.


Not calling anyone out on this, but lets get the cold hard facts and not what the overhead display states or a incorrect odometer states.


Next lets talk about 6 MPG's in the city!.....

 

Yeah, it does happen. When I lived in Des Moines the station down the street from me was famous for bad gas. Had to spend half an hour purging the fuel line once just to get the truck to start....

(On a side note, this station also had "magic" gas pumps. According to the pump they could fit 8.5 gallons into my 6 gallon gas can....)

 

Call the weights and measures department and turn their *** in! You don't have to leave your name or information. Just lodge a complaint and consider a truck there in a hour. I have to do this to the plants I inspect. http://www.iowaagriculture.gov/weightsandmeasures.asp

 

I am starting to get frustrated also with my mileage. Thursday i found a vaccum leak on the evap test port. The one with the green cap on it. At least that is what I think it is. The hose was cracked and split down the side. I replaced the hose and reset the engine codes. I filled up at work friday and drove home. Then I drove to Waco texas that night where the truck sat all weekend. I got in it Sunday and drove home. This morning i get in it and drive to work. As i get to work the low fuel light comes on. All in all it was 261 miles on an entire tank of gas. I refilled this afternoon and was 20.1 gallons. That is just a little over 13 mpg. This was 95% all highway miles running between 65-70 mph. My Rpms at 70 are around 18-1900. Also when i got home tonight I rechecked any codes in the computer and got an evap malfunction code. What would make it malfuntcion and would that cause the horrible fuel mileage. I'm almost to the point of putting it up for sale. Right now my f250 is cheaper to drive.

 

when was your last tune up? did you use champion copper core plugs? open the hood at night and check for arcing wires.

also check the air pressure in your tires (this can make a HUGE difference), also have you made any changes to the truck lately besides fixing the evap leak?

 

I actually changed the plugs about 2 weeks ago. Yes, they were champions and gapped at .040. There are no plugs to change.(4.7). The tires are pumped up to 50 PSI. Yes that is high but the tires are rated for 80 max and I was hoping it would improve mileage. The oil is new as well as the filter. You should know I just put this motor in during Christmas time off from work. It runs fantastic. Also this mileage is with out running A/C at all. The tires are 245/70-16s however are mud grips and I'm sure slightly heavier but I dont think its the cause of such low mileage. Seems like i should be around 18 hwy cause it is 4wd. I would be happy with that.

 

if it is a new engine it will take a few thousand miles to break it the engine (this applies to a rebuild too), yes the 4.7 should be giving you around 18 highway in the summer, the cold air drags that down to around 16 (at least for me), also how long did you let it warm up(if at all) the mud tires will hurt your mileage, but i wouldnt think it should hurt that badly

 

Just hold onto it. Your Mud tires are sucking it down, also 50 is too high and can cause more harm then good. Also you have non-OEM sized tires on so you are actually getting more mileage then you think. Take a GPS with you and record the actual mileage drivin. Then divide that into your gallons used.