Speedo Variance

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Nov 5, 2006 | 09:41 AM

jlalanas

Thread Starter

More Turbo

Joined: Feb 2006

Posts: 565

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From: Middletown,NJ

Speedo Variance

The other day I was on the highway in my F150 and my buddy was behind me in his Chrysler 300. Being curious to verify my speed, I called him and his speedo was reading almost 10mph lower than mine. Could that be right?

Couple things to note:

I have larger than stock tires on my truck (325 65 18s) and have an edge evolution tuner with the correct tire size programmed in. The edge has a speedo readout which is always a couple mph slower that what I show on the dial. When you program the edge for the larger tires, does that update the speedo in the truck or only the edge itself?

Anyone have any experience with this stuff?

Thanks.

Nov 5, 2006 | 11:02 AM

F150Texan

Posting Guru

Joined: Mar 2004

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From: Hockley, Tx.

Best and most reliable way to check true speed is with a handheld GPS

Nov 5, 2006 | 11:27 AM

wildcard30

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Joined: May 2003

Posts: 1,666

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From: Sunny tourist infested FL

My Speedo reads 3 MPH faster than my GPS.

Nov 5, 2006 | 02:05 PM

Tylus

MMNC (SS)(Ret)

Joined: Mar 2004

Posts: 11,606

Likes: 151

From: SE Georgia

my speed reads 2-3 mph slower than my true speed. I'm thinking my speedo didn't get reprogrammed when the dealership put the bigger rim/tire combo on though

Nov 5, 2006 | 02:59 PM

WhëëlMå1

Super Moderator

Joined: Oct 2002

Posts: 8,547

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From: MA

You have to ask them to reprogram the speedo in your truck. Sometimes they charge you, sometimes not.... (mine didnt). Also, you can only reprogram it 5 times (per Ford). Also, the Edge does not touch the speedo in your dash.

Nov 5, 2006 | 06:28 PM

derek4343

Senior User

Joined: Jun 2005

Posts: 332

Likes: 2

when i spoke to edge,they told me that their programmer was more accurate then fords speedo because it reads right from the computer

Nov 5, 2006 | 10:58 PM

2004f1504X4

Senior User

Joined: Feb 2006

Posts: 123

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if you have edge and a gps you can adjust the tire size until it gives you very close reading to the gps. I could not get it to read the same. There is an error in both gps and the speedo!