Gas milage problems

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Jul 9, 2004 | 03:30 PM

achiro

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Gas milage problems

I have around 7000 miles on my 6.0, fx-4 crew cab. First few tanks continued to increase milage up to around 19-21mpg. Then had oil changed, next tank dropped to 13, stayed there until I took it to the dealer. They worked on it, "we resat a couple of settings in the computer", next couple of tanks back up around 19-20. Sudden drop back to 12.5. Took it in today(felt I got the shaft or at least the big blow off) they tested it and got 16.2mpg and said it was fine. Even IF its 16.2 that seems low when I was getting 20!
I noticed a couple of others complaining of similar problems. Any suggestions, comments???
I also pulled a john boat that can't weigh 1500 pounds and only got 11, that was just before the last two tanks mentioned before.

These are highway miles, no idling, no towing. 70mph top speed.

I'd like to know anything I can about this issue to "educate" my local service department.

thanking everyone in advance.

Last edited by achiro; Jul 9, 2004 at 03:53 PM.

Jul 9, 2004 | 04:33 PM

SBV45

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From: Central Texas

How are you calculating your mileage? By the overhead meter or by actual miles divided by the gallons of fuel consumed? I assume you fill to the exact same mark in the filler neck each time?

Quote:

They worked on it, "we resat a couple of settings in the computer", next couple of tanks back up around 19-20.

That doesn't jive. There are no computer settings for them to adjust other than clearing codes or disconnect the battery to clear the FICM & TCM memory.

19-21 miles is outstanding. The oil change is suspicious. Who did the oil change? What oil was used? If they put 15 quarts back in, then it is too much. Check your dipstick. It should only be in the "crosshatched" area anything more than that is overfilled and could affect mileage although not that much.

Jul 9, 2004 | 08:16 PM

mrc59

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From: Metro DC

Indeed, watch the calculation method. You can't trust the overhead, and the only way to be sure hand-calc is right is to fill to the brim. This takes time because of fuel foaming. I have a 10% difference if fuel added between the first click off at the pump (same station, same pump every time) and fully topped off.

Jul 9, 2004 | 08:45 PM

tn mac

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Good luck on your fuel mpg problem,been working on mine since last august with very little luck. I believe there are some trucks that do good and others that dont and if you get one that doesnt your out of luck.

Jul 9, 2004 | 11:25 PM

achiro

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I am calculating it myself, the computer read out isn't even close although the average does drop when I am going through the lower milage periods. I do top it off completely.

tn mac, what have you tried?

Anyone know what would cause this other than the oil issue?

Jul 10, 2004 | 06:13 PM

tn mac

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I have tryed just about evry thing possible the truck shows no coded so ford says there is nothing wrong, I am getting ready to try and get them to buy it back and try to find 2003 7.3, in good shape. and let ford test there engine on some one else.