WTB, Rough Country Speedometer Calibrator

[belchfire]

Who has a Rough Country Speedometer Calibrator that they would sell cheap or rent?  I want to buy one, but for a single calibration, $140 seems steep.  I'm thinking I could buy yours and half your cost AND mine.  Anyone?

[belchfire]

OK, PSA:

 

I found two of these units on FB marketplace.  One was $70 and one was $100.  The clue was a comment on one that said " Used but removed and unlocked ", so I did some investigation.  The best information I have been able to find was on Amazon Questions:

 

 

Looks like it will only work with one VIN.  If the cost to buy a new license is the same as a new unit, then it won't be any good to buy a used one.  *sigh*.  Looks like I'm in this for $140 or nothing.

[TX_MattyIce]

I just got mine. I’m still off by like 1-2 mph. I’m running 285/75/17 they are 33.83. I had to drop the size to 33.25 to get close to the mph on the GPS on my phone. I was off 6-7 mph on the freeway before fixing it.

[belchfire]

18 hours ago, TX_MattyIce said:

I just got mine. I’m still off by like 1-2 mph. I’m running 285/75/17 they are 33.83. I had to drop the size to 33.25 to get close to the mph on the GPS on my phone. I was off 6-7 mph on the freeway before fixing it.

Yeah, I experienced the same thing.  Mine are 275/70/R18 (calculates to 33.15") and they measure 33" wide, side to side, but standing, they are only 32" tall.  I entered 33" to begin with, but I was still slow at the speedometer, so I backed it down to 32.25" and I'm spot-on now.  Many reviews on the speedo calibrator said you have to play with the number to find the effective rolling diameter.  It has to do with the sag in the tire at rest.

 

It's definitely worth the price, because it changes the shift points in the transmission and it drives better.  No more lugging at 60 mph.  Once I got it dialed in, not only is it reporting better gas mileage (because it's registering more miles in the same distance), but I'm also using less fuel each week, so my fuel mileage has actually increased.

[dieselfan1]

 I tried to download the programming on mine and it downloaded but then it wouldn't install the programming on the calibrator.

I'm returning it.

[tmo]

OK, PSA:
 
I found two of these units on FB marketplace.  One was $70 and one was $100.  The clue was a comment on one that said " Used but removed and unlocked ", so I did some investigation.  The best information I have been able to find was on Amazon Questions:
 

 
Looks like it will only work with one VIN.  If the cost to buy a new license is the same as a new unit, then it won't be any good to buy a used one.  *sigh*.  Looks like I'm in this for $140 or nothing.

From what I know once it has been uninstalled/unlocked from a vehicle it can be added to a new one. You can’t have more than one at a time.

[belchfire]

21 hours ago, tmo said:

From what I know once it has been uninstalled/unlocked from a vehicle it can be added to a new one. You can’t have more than one at a time.

And how would you do that?

[Huntingfool]

I bought a used Hypertech that was used but unlocked and it worked fine. Got it for $70. The original user must plug it back in to their vehicle and set their vehicle back to stock programming. That unlocks the device.