RPMs @70mph?

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Jul 3, 2005 | 02:07 PM

#46

guydiver12

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Joined: Jul 2004

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From: north louisiana

F-250 3.73'S, 265/70/16'S. 2000RPM@70MPH INDICATED, 68MPH ON GPS AND RADAR

Jul 5, 2005 | 10:32 PM

#47

Beachbumcook

Got Diesel?

Joined: Jan 2004

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Quote:

Originally Posted by moebdick

Mine (3.73 5sp TS) runs ±2000RPM @ 70mph on the speedo also, but I have noticed once or twice that when I pass those radar speed trailers that display your speed, the sign reads 2 or 3 mph slower than my speedo does.

My Excursion new read 2 - 3 mph slower than actual and this was verified with my GPS unit. The dealer modifed the programming for a "fake tire size" and it corrected the speedo for me so 70mph is actually 70mph (not 67mph).

As well, at 70mph, my RPM's are +/- 2000 RPM's and that is with 3.73 gears.

Good luck,

Jeff

Jul 6, 2005 | 05:59 AM

#48

Grizz49

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Joined: Jan 2005

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F-250 Lareit CC4x4 6.0 psd, Job #2 build, 70 mph 2000, want better fuel mpg. Keep that tach just under 2000rpm.

Last edited by Grizz49; Jul 6, 2005 at 05:59 AM. Reason: spelling

Jul 6, 2005 | 06:45 AM

#49

Bruce S

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Joined: Jul 2004

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From: Audubon, PA.

speedo off

My speedo reads 2 mph over the gps. I have an E-350 with the standard wheels and tires. 3.55 rear. At 2000 rpm i'm just a hair over 70.

Jul 6, 2005 | 06:57 AM

#50

moebdick

Elder User

Joined: Sep 2004

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From: Nashville

Quote:

Originally Posted by Beachbumcook

The dealer modifed the programming for a "fake tire size" and it corrected the speedo for me so 70mph is actually 70mph (not 67mph).

That's interesting. Did he say what tire size he programmed it for?

Jul 6, 2005 | 08:29 AM

#51

Beachbumcook

Got Diesel?

Joined: Jan 2004

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Quote:

Originally Posted by moebdick

That's interesting. Did he say what tire size he programmed it for?

I can't remember if he increased or decreased the tire size by 1 or 2 %, but he said that the computer "would think" I had a different tire size and it would compensate and correct the mph reading.

After he did it... all was well. I think he decreased the tire size in the computer so it senses that the tires are spinning faster to go the same distance and this adds the 3mph that I needed to get my spedo to read correctly (no body quote me since this has been 2-1/2 years ago)?????

I now have 52,000 miles on my 2003 Excursion LTD 4X4. Have only had programing and lower radiator hose repaired. Oil changes every 5,000 miles with Motorcraft 15W-40, fuel filters every 15,000 and transmission every 30,000 miles. I puke no coolant except for a drop here and there and I get 17 - 18mpg on the highway and 15.5 - 16.2 in the city. My overhead is within .5 of actual hand calculations. The only aftermarket product I run is a dieselsite coolant filter (yes, i flushed the cooling system with distilled water when installed at 51,000 miles).

I do miss the tow-haul and pilot injection as it was when I bought it, but otherwise the truck does what I need it do do.

The purpose of the thread was RPM's.... and I am around 2,000 (1,800 - 2,500) at 70mph with 3.73 gears.

Thanks,

Jeff