I'm fairly new to FTE but I'm really enjoying it -- excellent site! I just bought my first Ford and my first diesel, a 2000 F250 PSD, CC short bed 4x4 with 41000 miles. I love it. I picked it up in Bend, Oregon, and was really happy when during my six hour ride home I averaged 18.2 miles per gallon. Two lane highway, up and down, fairly high elevation and speeds between 65-75 mph. I wasn't babying it.

When I got home (northern California) I immediately got it serviced, changed the oil and filter, etc., but didn't change the fuel filter. I put a half tank in it and averaged 16.5 around town. The next tank it went down to 15.5...then 14. Now, a month after my purchase, it's at 12-13 around town, even if I baby it under 2K RPM. On long, extended highway trips (no load), I'm lucky to break 16mpg. All my mileage numbers are actual, not off the overhead computer.

I don't know what the diesel is like in Oregon, and if perhaps the stuff in California is worse, but could fuel quality have this much effect on mileage? Could a used up fuel filter cause this drastic a drop? I read the fuel filter thread in the forum and have a new filter and some Stanadyne additive on order, so that'll be my next attempt to see if I can bring it up to where it was.

Being new to all this, I was hoping someone might have experienced something similar and could perhaps shed some light on this. Thanks a bunch.

PSDJB

 

I have a similar issue with my truck , as far as a major loss in MPG out of the blue. I traced my issue to the winter blend of fuel in my area being the cause. A new fuel filter i am sure will atleast help your situation , as well as the fuel additive...

 

I'd change the fuel filter and start adding Stanadyne when it comes. I faithfully add it at every fillup, and I also top off my tanks completely every time, to be sure I'm getting an accurate reading on my mpg. The onset of winter fuel, and increased warm up times, can have a significant affect on your mpg.

 

I've seen a little of the same thing and agree with the other two - probably the fuel. I just ordered a case of the Stanadyne, we'll see if it makes any difference ( got the lubricity for the winter and ordered some of the performance for spring).

I'm also stuck out here in Oregon where they don't regulate Octane or Cetane ratings (much less post them).

I know a guy who tests fuel for some of the local race clubs, and he has pulled as much as a quart of water out of a gallon of Gas ... don't fill up at Arco.

If they actually did random pump testing around here like they do in other places - 90% of the places would have to close

 

Thanks for the input. I'll wait and see how the additive and the filter affect the mileage, then go from there. And maybe I'll have to chip it and try and get an increase there.