Speedometer Calibration
 

I am new to this site and new to Ford ownership. I recently bought a 1998 F-150 with the 4.2L. It has different tires than factory on it so the speedo is off. I've read some posts about using the odometer and inputing a code but mine has an analog odometer so that is not an option.
Is there any way to calibrate the speedo to reflect the differnt tires?

Thank you.

Hmm......
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Talk to Ken (webmaster) see if a chip can have that programmed into it. I know on older vehicles there is a gear that be cahnged to reflect cahgnes in gear ratios, tire sizes. I THINK ours is the same way.

Speedo
 

I know on some there is a gear in the transmission but on the mazda tranny you have to take the rear housing off to get to it.

Dude, get a chip from motorhaven from Ken. www.motorhaven.com

Go to the Diablo chip for Fords section. They are $230 shipped to your door. It will totally fix the speedo AND give you some power to turn those big wheels to boot!

yea,

I agree with true 4.2!

I have 20's on my truck and i am just waiting to get enough money to buy a stage 2 diablo chip!

Do it!

Kman

What size tires are you running now, and what were the original size tires.

Here's a link that will tell you how much your speedo is really off.

http://www.intercotire.com/html/true-mph.htm

I personally think the SCT is a better chip from what Ive read. Go with the diablo if you have no need for custom programing :)

If all you care about is fixing your speedo then just get a "Superlift Truspeed" speedo calibrator.

It's infinately adjustable and can be self adjusted a million times, every time you change gearing or your tire size. I'm probably going to get one since I keep changing gears and tire sizes. Look here.

http://www.4x4wire.com/dodge/reviews/truespeed/