No need to correct speedometer after tire size change?

[crsevns90]

Do I need to do something to correct the speedometer reading on my 98 ranger if i change tire size? Or is it corrected automatically by the PCM? Thanks!

 

[V8 Level II]

For 1998 ~2000 Rangers, speedometer error can be corrected by using a dealer tool to access the GEM (RABS truck) or ABS module (4WABS truck). The PCM is not involved.

Limited speedometer corrections can be made in the PCM using a dealer tool in 2001+ Rangers. Larger corrections are possible with an aftermarket flash tuner.

 

[crsevns90]

So I will need to recalibrate the speedo if I put different size tires on. Correct?

 

[AngryLepercon]

So I will need to recalibrate the speedo if I put different size tires on. Correct?

You can. If it is not off too bad leave it the way it is if ya ever get pulled over just say you are waiting for the recalibrator in the mail. lol

 

[V8 Level II]

So I will need to recalibrate the speedo if I put different size tires on. Correct?

Your speedometer calibration will be wrong if you change the tire diameter.

 

[SteveThePirate227]

so...
how would you go about recalibrating? like on an '02?
becuase this is going to be a problem for me in a month or so.

 

[Earl43P]

.

For 1998 ~2000 Rangers, speedometer error can be corrected by using a dealer tool to access the GEM (RABS truck) or ABS module (4WABS truck). The PCM is not involved.

Limited speedometer corrections can be made in the PCM using a dealer tool in 2001+ Rangers. Larger corrections are possible with an aftermarket flash tuner.

.

 

[turin39789]

Is it possible to get the dealer tool? How much and where?

If not, anyone know what it costs to get the dealer to verify or change your settings? Just bought an 06 with slightly off-stock tires on it.

 

[Chris.S.]

How much are you changing tire size by? A couple inches won't make too much difference.

For the hassle, I wouldn't worry about it.

 

[98ranger4x4]

+1 going from a 235/75/15 (28'') to a 31'' only causes my speedometer to be off by 3 mph at 70mph (if it says 70, i am going 73)

 

[fordboi415]

Just go and buy a programmer and that will take care of you problem that way if you decide to change the diameter of tires again you'll be set and you won't have to keep taking your truck to the dealer, and it also serves as a code reader so if your CEL is on you'll know why, and you won't have to pay the dealer to check your truck out

 

[TwoTrackMind]

My TwoBits

When I bought my Ranger it had 235/75/15 on it with 3:73 gears. When I changed to 31" tires it also changed about 3mph. But when I put in 4:10 gears it was right back on the money. So thats another way for you to fix it if you want. (Also a good excuse to get better gears )

 

[V8 Level II]

Just go and buy a programmer and that will take care of you problem that way if you decide to change the diameter of tires again you'll be set

An aftermarket flash programmer cannot make speedometer corrections for 2000 or earlier Rangers. The OP has a 98.

 

[rangerbum]

Hey, sorry, I dont mean to thread jack, but I've been curious about something. With bigger tires, if you dont recalibrate, does the Odometer read lower?

 

[sean9721]

Hey, sorry, I dont mean to thread jack, but I've been curious about something. With bigger tires, if you dont recalibrate, does the Odometer read lower?

Yes.