Bad Mileage

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Nov 21, 2002 | 10:02 AM

Kingtim7

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From: Cocoa Beach, FL

Bad Mileage

My 99 SC 7.3 DEISEL only gets 13 mpg hwy empty. My 4dr dually got 18 and Ford says theres nothing wrong. I want to get a chip and exhaust but I want to fix this mileage problem first.

Nov 23, 2002 | 10:05 PM

goalie

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Bad Mileage

I could be your driving habits or your maintainence.Air filters if dirty will kill your mileage,as well as oil and fuel, so change these filters when you should.If you are heavy in the right foot then this could explain the low #s.

Nov 23, 2002 | 10:37 PM

Sam Wactor

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From: Jonesville La.

Bad Mileage

[updated:LAST EDITED ON 23-Nov-02 AT 11:43 PM (EST)]This seems to be a common problem from the research that I've done. Some of the Power Strokes get 20 mpg or better while some only get 13 mpg or so. No one so far has been able to explain it. Doing mods on the exhaust and the chip may be an answer that help solve the problem. By the way the down pipe and the chip are the first things that I'd try first to resolve this.
I'm not sure if your truck has a cat on the exhaust or not. If it does, I'd solve that problem too while I was at it.

Nov 24, 2002 | 08:52 AM

Kingtim7

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From: Cocoa Beach, FL

Bad Mileage

Thanks for the reply. I think I'll try a chip and down pipe and be satified with whatever mileage I get. My 4dr 4x4 dually 7.3 got 18 mpg no matter how I drove it and I thought I'd get at least that with my SC 7.3 4x4 SRW.

Nov 29, 2002 | 09:25 AM

powerstroker250

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Bad Mileage

Nov 29, 2002 | 10:00 AM

curmudgeon

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Bad Mileage

Are you sure your axle ratio is the same as the truck (the dually) you're comparing it to? My old '91 with 259,000 miles on it gets 19.5 MPG with an auto tranny, but it has a 3.55 "freeway axle" which was not easy to find. It runs 70 MPH at about 2100 RPM. If your axle is 4.10 or higher it's tough to get much better than 15-16.

Nov 29, 2002 | 03:45 PM

Kingtim7

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From: Cocoa Beach, FL

Bad Mileage

Both have 3.73. It might be a good idea to just trade it in or sell it and buy another. But I'll have to check milage before I take possesion. I hate getting stuck on mileage but I keep all my stuff clean and working right and one of the things I like about diesel is their efficiency. Plus I drive alot.

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Nov 29, 2002 | 05:05 PM

curmudgeon

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Bad Mileage

[updated:LAST EDITED ON 29-Nov-02 AT 06:34 PM (EST)]If it's NOT a 4WD and you really like the truck you could always throw a 3.55 axle in it, but that would only buy you maybe 3 MPG better than your 3.73, and you couldn't tow as much. One reason I like the old IDIs is you can dial up any mileage you want with the fuel metering rate screw on the injection pump. I tweaked about 6 more MPG out of mine before the power loss was very noticeable. Is it possible to do that on your PSD?

Oops, just noticed that it IS a 4x4, so to paraphrase Tony Soprano - "Fugeddaboudit"! Good thing they let us go back and edit these things....