NEW TIRE SPEEDO CALIBRATION?

[Polaris Man]

mine came in today. Was super easy and quick to recalibrate. Takes less than 5 mins and all done. That simple. Checked it against Waze right after installing new tires and lift today. Speed was off approx 4-5 mph. Got home recalibrated with RC and boom! dead on now with the gps in my phone via Waze. Oh new tires are Nitto Ridge Grappler 295/60 R20

Got mine, updated it, plugged it in, says STARTING...

Said that for 10-15 mins with no change. RC is sending a new one.

 

[Ty9122]

My local dealership says they will do it for a half hours labour rate with their scan tool

 

[ExcursionDiesel]

My local dealership says they will do it for a half hours labour rate with their scan tool

Might want to check. Others have reported that dealers can only load calibrations for stock tire sizes that come on different models.

 

[Troop2865]

I ordered the RC speedometer calibrator. It was shipped quickly and I had it in a couple of days.

It was pretty easy to use. However, I had to tell the computer I have 33 inch tires to get it to read correctly. My tires are Nitto Ridge Grappler 35-12.50-18’s that are actually 34.75 inches. I checked speed with GPS. At 33 inch tires the speedometer is right on.

 

[Shannonw]

Just order a Tazer DT and you can change your tire size, plus get WAY more features with it. https://zautomotive.com/product/tazer-dt/

 

[WRH]

Heading in for an oil change / recall today. How big of a deal is it to flash back to stock first?

 

[nicodywill]

Heading in for an oil change / recall today. How big of a deal is it to flash back to stock first?

If you have the Rough Country unit you do not need to.

 

[WRH]

If you have the Rough Country unit you do not need to.

I have the Rough Country, but just the unit that flashes for tire size.

 

[ant0064]

I just used the RC Calibrator on my truck yesterday...easy to use and very effective. I keep hearing about flashing back to stock...I assume this means restoring it to factory settings? If so, how do you do that...in other words, what size tire is factory? I realize its 31.9" or so, but under load that changes. Also what is the purpose of flashing back to stock? Thanks!

 

[nicodywill]

I just used the RC Calibrator on my truck yesterday...easy to use and very effective. I keep hearing about flashing back to stock...I assume this means restoring it to factory settings? If so, how do you do that...in other words, what size tire is factory? I realize its 31.9" or so, but under load that changes. Also what is the purpose of flashing back to stock? Thanks!

I thought there was a blanket option to just "revert to stock". No clue why you would want to go back to the stock setting though. The Rough Country unit does NOT affect warranty in any manner and was suggested to me by my dealers service department manager. I've since taken in my pickup for servicing and had no issue.

 

[RodRow]

The Rough Country Speedometer Calibrator works perfectly on 2019 DT Rams.
One note of caution...do not have any codes active when calibrating or it royally screws up!
I had low wiper fluid when I tried to update my tire size, and it took me a week and a trip to the dealership to fix the programming issue.
Also, check your programming with an app on your phone (like Waze) to ensure that the speed is aligned. It took me several adjustments to tune mine exactly.

 

[ant0064]

I thought there was a blanket option to just "revert to stock". No clue why you would want to go back to the stock setting though. The Rough Country unit does NOT affect warranty in any manner and was suggested to me by my dealers service department manager. I've since taken in my pickup for servicing and had no issue.

The reason why I ask is because people keep talking about "flashing" it back to stock if they have to take it to the dealership for recalls or any other issue that they have to plug in for. Not sure why.

 

[RodRow]

I just used the RC Calibrator on my truck yesterday...easy to use and very effective. I keep hearing about flashing back to stock...I assume this means restoring it to factory settings? If so, how do you do that...in other words, what size tire is factory? I realize its 31.9" or so, but under load that changes. Also what is the purpose of flashing back to stock? Thanks!

When you connect the RC Speedo Calibrator, it gives you the “option” to return to stock. It memorizes the stock setting before programming the tire size, which is why you don’t want to use it on more than one vehicle.
The RC instruction strongly suggest you returning to stock settings before taking into the dealership for any reason as it can potentially give a “false positive” for certain diagnostic tools.

 

[Joeyp]

The Rough Country Speedometer Calibrator works perfectly on 2019 DT Rams.
One note of caution...do not have any codes active when calibrating or it royally screws up!
I had low wiper fluid when I tried to update my tire size, and it took me a week and a trip to the dealership to fix the programming issue.
Also, check your programming with an app on your phone (like Waze) to ensure that the speed is aligned. It took me several adjustments to tune mine exactly.

Going from 265's to my 35's Im only off a few mph so I'm just going to let her ride and not even worry about the calibration.

 

[ant0064]

When you connect the RC Speedo Calibrator, it gives you the “option” to return to stock. It memorizes the stock setting before programming the tire size, which is why you don’t want to use it on more than one vehicle.
The RC instruction strongly suggest you returning to stock settings before taking into the dealership for any reason as it can potentially give a “false positive” for certain diagnostic tools.

Thanks for this info!

 

[ant0064]

Going from 265's to my 35's Im only off a few mph so I'm just going to let her ride and not even worry about the calibration.

I did the same thing and was 4-5 mph off at higher speeds....about 9.1% change. It definitely affects the speed, odometer, and MPG reading and I believe the actual gear shifts.

 

[Joeyp]

I did the same thing and was 4-5 mph off at higher speeds....about 9.1% change. It definitely affects the speed, odometer, and MPG reading and I believe the actual gear shifts.

How can it affect the gear shifts? It's not reprogramming the ECU.

 

[ant0064]

How can it affect the gear shifts? It's not reprogramming the ECU.

Not sure, hence why I'm asking these questions.

 

[Joeyp]

Not sure, hence why I'm asking these questions.

I think some of these devices may claim to, but the gearing is the gearing. My truck is shifting the same as it was with the smaller tires on it. The only difference is the 3.21 will seem more sluggish with the larger tires and maybe shift back and forth between 7th and 8th gear a lot if you're doing highway driving (small hills or a headwind)

 

[ant0064]

I think some of these devices may claim to, but the gearing is the gearing. My truck is shifting the same as it was with the smaller tires on it. The only difference is the 3.21 will seem more sluggish with the larger tires and maybe shift back and forth between 7th and 8th gear a lot if you're doing highway driving (small hills or a headwind)

Gotcha...I ordered mine with a 392 gear ratio but I honestly haven't noticed a difference in shifting before and after the RC calibration. It definitely fixed the speed, MPG and odometer though so I guess it just depends if you want it to be accurate or not. I'm just going by what the buzz is and trying to figure out if it makes an actual difference with the transmission.