Speedometer calibration

[Mountain Whiskey]

I'm using a Tazer JL, which I afterward used on a JT, and then switched over to a DT. It works great on my '20. And I have all the park sense stuff.

So when I trade in my JL I can pull my tazer and use it on a Bighorn?

 

[NHjake98]

Thank you for the info! Was it really easy to work and figure out? I was looking at the Rough Country calibrator. If im going to spend the money at a dealership id just rather buy the product.

It was easy. The instructions they give you suck, but their CS is good and they sent me a video on where to hook up the bypass gateway. Once they did that, it took all of 15 minutes and it was done.

 

[mmondich]

So what is the consensus? Can the dealership do the calibration or not? I went to 33" (275/60/20s) on my '21 Laramie and have seen a difference in the speedo. The fuel mileage is off by about 3% I'm guessing but the shift points don't seem to have any issue. The truck has 1600 miles on it and I'm wondering if this is something that can be done when the truck is getting it's first L.O.F.

Thanks!

 

[Condor757]

So what is the consensus? Can the dealership do the calibration or not? I went to 33" (275/60/20s) on my '21 Laramie and have seen a difference in the speedo. The fuel mileage is off by about 3% I'm guessing but the shift points don't seem to have any issue. The truck has 1600 miles on it and I'm wondering if this is something that can be done when the truck is getting it's first L.O.F.

Thanks!

Yep. My dealer did it for $130. They do the recal as well as add the new tire size to the VIN. In and out in 30mins

 

[Morenar]

So I wanted to confirm. Dealerships can do recalibration for speedometer? I have a 2021 and noticed that Rough Country's calibrator does not support 2021 due to a different ECM.

 

[mmondich]

Yep. My dealer did it for $130. They do the recal as well as add the new tire size to the VIN. In and out in 30mins

$130 is kind of steep for a simple re-calibration......geez.

 

[Condor757]

$130 is kind of steep for a simple re-calibration......geez.

The regular cost is $185.
If you go the OBD route it costs $250 and up... I didn’t need all the gizmos with the OBD so to me $130 was money well spent.

 

[frostymug]

I snapped a couple pics, first one is just steady foot on pedal 42MPH, and second is with cruise control on set at 48MPH. You can see both Waze GPS MPH (upper right-hand corner on screen) and odometer...Just in case people thought I was FOS.

I went up in tire size as well and noticed that Waze is also dead on with the truck's speedometer. However, I downloaded other GPS speedometer apps and also used my radar detector that has GPS and no other sources corroborate with Waze. I am thinking if perhaps Waze is somehow actually using the truck's speedometer as it's speed source vs. using true GPS like it does when it is not conneted to Carplay. Maybe that sounds crazy, but why is every other app not corroborating Waze's speed?

 

[frostymug]

OK this is what I did. Back in October I put on 33 inch tires on my Laramie sport 4 x 4. According to my Garmin which is not connected to my truck at all, my speedometer was off 2 1/2 to 3 mph over 60. I then downloaded the Waze app on my iPhone and used Apple CarPlay and according to Waze My speedometer was exactly correct. Last week I checked again with my Garmin and again my speedometer was off 2 to 3 mph. I then downloaded on my iPhone another Speedometer app and according to this app my speedometer was off 2 to 3 mph. In other words I was going faster than my speedometer said that I was. So i then completely disconnected my iPhone from my truck, no Bluetooth at all and use the Waze app strictly on my iPhone. The Waze app without the iPhone connected to my truck at all shows that my speedometer is off 2 to 3 mph, again I am going 2 to 3 mph faster than my speedometer says I am. I think if The Waze app is connected to the truck in anyway such as Apple CarPlay that the Waze app uses the navigation unit in my truck as does the Speedometer to determine the correct miles per hour. So I am installing a taser DT to correct the speedometer. I have one in my JL wrangler rubicon and I have never had any problems with the Taser.

Oh wow, I just posted that this is my theory, and now reading your post my suspicions are confirmed. A lot of people on here are thinking their truck auto-calibrated because they are using Waze on Carplay to verify their speed matches the truck's speedometer. Looks like a lot of guys got fooled into thinking their truck self-calibrated. Would love to see independent verifications of recalibration that aren't using Waze as the "proof".

 

[Ellisstrong]

Oh wow, I just posted that this is my theory, and now reading your post my suspicions are confirmed. A lot of people on here are thinking their truck auto-calibrated because they are using Waze on Carplay to verify their speed matches the truck's speedometer. Looks like a lot of guys got fooled into thinking their truck self-calibrated. Would love to see independent verifications of recalibration that aren't using Waze as the "proof".

I realized after continued testing that it is the waze app showing the trucks speed as shown on the dash through CarPlay.

 

[ajosephngs]

Waze, while connected, shows different mph for me. I just went to 295/70 and I’m off by 5 mph at 70. Bigger tires and waze is reading that I’m going faster than the dash which would make sense.

 

[Pyleketerson]

So I wanted to confirm. Dealerships can do recalibration for speedometer? I have a 2021 and noticed that Rough Country's calibrator does not support 2021 due to a different ECM.

Mine refused.

 

[kd908070]

Discount Tire | Tires and Wheels for Sale | Online & In-Person

www.discounttire.com

This website has the tool to calculate the difference of the speed between the current & future size.

 

[Morenar]

Mine refused.

Spoke with mine a few months ago and they stated they could do it. I knew they could as they do tons of custom Jeeps and Ram's. They charge $125 I think it was for the one time change.

 

[Mhorton814]

IF anybody is in need of recalibration I have a FlashCal available for sale for 2019 RAM

 

[Dcsnet]

Does anyone know for sure sure if the Hypertech 752504 works on 2021 Ram 1500 with Park Sense and brake assist, I do not have Park assist. I have the RC 90019 but it still disables Park Sense.
Thanks
Don

 

[KC@TX]

I have a 2019 Ram 1500 5.7. I installed larger tires going from 275/55/20 Falken to Michelin 275/65/20 Ltx AT/2 E load. I had a speedometer difference of about 4 mph. After reading many reviews & forums I ordered the Hypertech 3400 from Amazon. It seems some folks had issues in the past with larger tire size calibration messing up the park assist or park sensors. I believe that those instances usually involved larger tires than what I installed. It didn't affect my park sensors or anything else. The Hypertech 3400 was straight forward and simple. I updated it on my laptop to ensure it had the most up-to-date info, and once hooked up to my truck, it took 10 min. or less to program. Using 33.50 as the tire size, my speedometer is spot on now, with no issues whatsoever.

 

[theblet]

I have a 2019 Ram 1500 5.7. I installed larger tires going from 275/55/20 Falken to Michelin 275/65/20 Ltx AT/2 E load. I had a speedometer difference of about 4 mph. After reading many reviews & forums I ordered the Hypertech 3400 from Amazon. It seems some folks had issues in the past with larger tire size calibration messing up the park assist or park sensors. I believe that those instances usually involved larger tires than what I installed. It didn't affect my park sensors or anything else. The Hypertech 3400 was straight forward and simple. I updated it on my laptop to ensure it had the most up-to-date info, and once hooked up to my truck, it took 10 min. or less to program. Using 33.50 as the tire size, my speedometer is spot on now, with no issues whatsoever.

The parking nannys won’t be affected if the tires are 35” or less.

I recalibrated mine with Jscan and my iPhone.

 

[ozzie280]

Hello,

This is my 1st time posting to the group. i have been search the forum and could not get a straight answer. I have a 2021 Ram limited with Level 1 equipment group. it includes the park assist, adaptive cruise control as well as the pedestrian E braking. I installed 33' tires, and my speedo is off. has anyone used the Hypertech programmer on their truck and did it mess with the Level 1 equipment group bells and whistles? If you have, please share your experience and the part number of the unit you used.

Thanks in advance,

Ozzie

 

[ozzie280]

I have a 2019 Ram 1500 5.7. I installed larger tires going from 275/55/20 Falken to Michelin 275/65/20 Ltx AT/2 E load. I had a speedometer difference of about 4 mph. After reading many reviews & forums I ordered the Hypertech 3400 from Amazon. It seems some folks had issues in the past with larger tire size calibration messing up the park assist or park sensors. I believe that those instances usually involved larger tires than what I installed. It didn't affect my park sensors or anything else. The Hypertech 3400 was straight forward and simple. I updated it on my laptop to ensure it had the most up-to-date info, and once hooked up to my truck, it took 10 min. or less to program. Using 33.50 as the tire size, my speedometer is spot on now, with no issues whatsoever.

Do you have the park assist and adaptive cruise control? did iy affect those systems?

thanks,