new 250 sd

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Feb 26, 2003 | 06:10 PM

mekons0

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From: manhattan, ks

new 250 sd

Just bought a used 250 psd old owner said it got 18 mpg. I only get about 10 now. I question if the used car lot took out the preformance chip. Where do I look or how can I tell?

Feb 26, 2003 | 07:17 PM

Monsta

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From: Washington State

new 250 sd

What makes you think it had a chip before?

What year truck?

How do you know you're getting 10?

If you're really only gettin' 10 then something is amiss or you gotta stop flooring it so much!

If you got a Super Duty then you can pull the computer (under dash; lower left behind the parking brake) and see if the plug that usually covers the access port is removed. Of course doing so (pulling the computer) will either reveal a chip or not.

I cannot imagine a chip giving you an 80% increase in mileage.

Feb 27, 2003 | 09:48 AM

NoMo

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From: OK

new 250 sd

First, WELCOME to the site!

Assuming you're not driving the **** out of the truck, one of the first things to do is check all the fluids. If the engine oil is over-full, you may have a serious injector issue. Next is the fuel filter. Even if the previous owner says it is fairly "new", change it anyway. If that doesn't help the mileage, then I'd start looking for stuck brake pads and wheel bearings.

Feb 27, 2003 | 05:32 PM

mekons0

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From: manhattan, ks

new 250 sd

2001 f250 psd with 48k miles
I looked up the owner by title ....he's from Texas. Don't know if he was just blowing smoke but said it had a performance chip. He pulled 31' travel trailer all the time at 16-18 mpg. Trashed it in a ditch and insurance sold it to a dealer. I got it from the dealer but don't really know whats what.
I pulled a light car hauler for 600 miles. Performed well, no real smoke, good acceleration. Just bad mpg.

Feb 27, 2003 | 05:52 PM

GAV10

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Joined: Oct 2002

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From: Fayetteville (Atlanta) GA

new 250 sd

Let's see a 31 ft. trailer has got to weight 8,000 plus pounds. I really doubt the previous owner was getting even 16 mpg towing. I may get flamed by the oil burners but that is hard to believe. You should be getting 16 to 18 around town unloaded with a PSD anyway. Check your tire pressures. Increase them up to the max for a couple of tank fulls and see what happens. It may ride quite a bit rougher, but try it and see what your MPG does. Other factors to consider... gearing 3:73, 4:30's or 4:10's. Are you running oversized tires ? Is it a 4x4, front hubs not unlocking? Like Nomo suggested change all the filters and do a good rountine servicing.

BTW You are calculating your MPG manually right ? Not using the overhead computer, if so equipped.

Mark

Feb 28, 2003 | 09:35 AM

Waxy

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From: Calgary Canada

new 250 sd

Chip or no chip, 16-18 mpg towing a 31' trailer is completely unrealisitic IMHO. I'd say numbers closer to 12-14 mpg would be more reasonable.

Check the diesel forum, there are several threads in there on fuel mileage.

I would also agree with what Nomo said about routine maintenance.

Waxy

Feb 28, 2003 | 09:50 AM

NoMo

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From: OK

new 250 sd

I concurr that 18 MPG is pretty hard to believe when towing a TT that big. With my little 2WD GMC, I only get 18+ running empty.

With diesels, the "optimal" engine speed for economy is 2000 RPMs. Once you exceed that, mileage really drops off.

PS: Unless someone has changed out the OEM gears, you have a 3.73:1 ratio. That is all that Ford offers in the F250 w/PSD.