Rough Country Speedometer Calibrator

Wow. Glad to see this thread is still alive!

I ran then hid mine behind the left kick panel

 

I live in CA and ordered it right off their site.

 

When you install it just leave the usb plugged in and find somewhere to tuck it so you can reach later. Really easy once you have it apart.

 

Its better to leave it plugged in behind the speedometer cluster so the cord can reach over to a lap top when making adjustments. My tuner who did my KDMAX tunes got mine dialed in perfect when I went to 285s.

 

Installed the Rough Country speedo calibrator on my 2018 Off-Road with 285/70R/17s. It immediately and accurately corrected the speedo. It did NOT restore the OEM shift points as advertised by Rough Country. I'm not surprised and plan to get the OTT anyway, but be advised if you were counting on that. I haven't yet figured out whether it corrected the odometer, or not. Does anyone know where the odometer reading is taken?

Update: I confirmed that the speedo calibrator DID also correct the odometer reading. It also corrected the estimated MPG reading. It appears that my 3" lift + 285/70R/17's did NOT appreciably reduce my gas mileage. (~16mpg combined city / highway; ~20mp highway). Since installing the oversized tires, I've been driving in ECT/PWR mode which helps get the shift points closer to stock given the slightly taller gearing from the oversized tires.

Side note: There is a feature in the GPS settings to recalibrate the GPS to new (and different) tire size. Detailed Navi Settings / Calibration / Tire Change. The notes in manual say:

This navigation system uses tire turning
data and is designed to work with factory-
specified tires for the vehicle.
Installing tires that are larger or smaller
than the originally equipped diameter
may cause inaccurate display of the current
position. The tire pressure also
affects the diameter of the tires, so make
sure that the tire pressure of all 4 tires is
correct.

I have no idea whether this has any effect beyond the GPS mapping system. Does anyone know?

 

This might be dumb question, but what's the difference between in-line speedometer calibrator modules (like the RC or Hypertech that are discussed in this thread) and something like the calibration programmers that Hypertech sells? It seems like the programming unit has additional features like the ability to read and clear DTCs and potentially to also provide additional tuning functions? The price for the programmer is around $205 on their website whereas the RC in-line module is $160 and the Hypertech module is $250. Is there a reason to prefer the in-line module?

 

My guess is the "calibration programmers" are not compatible with the Tacoma. Check their website further by putting in your vehicle specifics into their product finder. I put my specifics in and the only Hypertech product returned was the in-line unit.

 

Ahha, that would make sense. A teacher once told me there are no dumb questions, only dumb people who ask questions. I think I just proved his point.

 

Easy mistake to make. If it makes the decision any easier, the RC is the same thing as the hypertech just in different packaging at a lower price point. I went RC and when I downloaded the software and drivers it was all labeled hypertech

 

I just got the RC inline Speedo Calibrator, but I have a '23 TRD Sport. When I plugged the module in to the USB and ran the application on my computer, it does not allow me to choose a '23 Toyota, in fact, the only options available for 2023 are Jeep and Ram. I was able to go down to the 2021 Model year and Toyota appeared, thanks to the suggestion of VaToy from here. Has anyone had this issue and had to use a different year than the year of their exact vehicle?

 

Does it also display the correct mpgs?

 

I don't recall that question being asked before, interesting, I don't know but I doubt it. However, I don't think most people believe the Toyota calculated estimate to begin with. I only use the getting low on fuel notice. I do wish somebody would come up with a way to correct the cruise control with a change in tire size.

Edit: The Rough Country unit works just fine, correcting Speed display and the Cruise Control. 19 Feb 2024

 

What is wrong with the cruise control when calibrating to bigger sizes?

 

The Rough Country device only changes the CANBUS signal to the speedometer to modify the displayed MPH, nothing more. The Cruise control is independent of the Speedometer and is found somewhere else in the vehicle, still connected to the CANBUS but unaffected by the Rough Country device. In my current configuration I have to set the cruise control to 62 MPH to go 65MPH. It will get worse when I get even bigger tires. 255/85R16

Edit: Updated unit and installed. Cruise control displayed just fine, as did the speedometer. I recommend. 19 Feb 2024

 

interesting. how has no one else mentioned this?

 

Inattentiveness, I suppose or they don’t use the cruise control much. This has been covered in other threads.

To illustrate this quandary a bit more. I have two GPSs on the dash and an UltraGauge, the Ultra displays the CANBUS speed which is the same as the cruise control. The GPSs display the vehicle speed. The only way to make them all the same, I believe, is to alter the wheel speed sensors input to the Skid Control ECU. Toyota makes no allowance for tire change sizes, hence the box that goes behind the speedometer.

Edit: Updated unit and installed. Cuise control displayed just fine, as did the speedometer. I recommend. 19 Feb 2024

 

Search this thread only for "cruise" and you'll get 22 results. Everyone has their own beliefs as to why the cruise control set speed doesn't display properly.

 

I had the hypertech on my 17 and never noticed this but also made sure it was running the current firmware. A post a few pages back mentioned that he also updated it to latest and radar cruise setting matched digital/analog speed.

Lastly, Amazon has the Hypertech for $143 making it cheaper than the RC unit

 

I'm very happy with my Hypertech on my 2018. I know the cruise control will hold at whatever speed it set it at, so I don't really care that the MID shows the wrong number as long as my speedometer is correct, which it is.

 

Interesting about the cruise control. I have a hypertech on my 23 and the cruise works as intended. Had one on my 17 colorado and it all worked fine as well.