dealer said Chrysler wants $350 to "subscribe" to larger tires to adjust my speedometer?!?!?!?!?

[WXman]

What did you use to program it? When I was deciding which programmer to buy, that was the common issue with all of them, and I tested with my Hypertech, it was like I had pressed the off switches and couldn't turn them back on. Personally I never wanted the sensors to begin with but couldn't get my heated seats and steering wheel without that too haha

I'm using an old Tazer that I bought 4 or 5 years ago to use on a JL Wrangler, then used it on a Ram, then a Gladiator, and now I'm using it on my 2022 Laramie. Lol. Works like a charm on 18.1.6 firmware.

 

[lawmann8]

I have a 2021 1500 Limited. 2 weeks ago I had Discount Tire replace my stock 285/45r22 for 285/55r22 Recon Grapplers. As such, my speedometer is off by about 6 MPH at 60MPH. I have read on this board many went to their dealer for $125-$150 and had the speedometer adjusted so I set an appointment. I went today and service rep came back and said to "get the codes" Chrysler wanted me to "subscribe" to larger tires at a cost of $350. What the hell is this? Needles to say I did not pay and left.

I bought a ALFAOBD from Amazon for $139.00 and a security bypass cable for $18.00. I then searched YouTube for videos on tire size programming. I found plenty of them and followed each step. Had mime 2022 Ram 1500 reprogrammed in about 10 minutes. I hope this helps.

 

[Idahoktm]

I bought a ALFAOBD from Amazon for $139.00 and a security bypass cable for $18.00. I then searched YouTube for videos on tire size programming. I found plenty of them and followed each step. Had mime 2022 Ram 1500 reprogrammed in about 10 minutes. I hope this helps.

AlfaOBD is an app that sells on the Google Play store for $50.

 

[lawmann8]

AlfaOBD is an app that sells on the Google Play store for $50.

You are absolutely correct. The OBD port device was a MX+ from Amazon.

 

[Choate]

Jscan user here. Updated tire size twice and left fogs on w high beams. I didn’t have a need for all the other stuff and Jscan is an iPhone app that’s super easy to use

 

[Starkhaus]

Apologies for the slight sidebar, but what are the pros to getting a calibration done aside from the speedometer being accurate again? Im aiming to do 35s if that changes anything

 

[VectorZ]

Jscan user here. Updated tire size twice and left fogs on w high beams. I didn’t have a need for all the other stuff and Jscan is an iPhone app that’s super easy to use

Same

 

[VectorZ]

Apologies for the slight sidebar, but what are the pros to getting a calibration done aside from the speedometer being accurate again? Im aiming to do 35s if that changes anything

The miles your truck accumulates will be more or less over time, significantly if you drive a lot. This will effect your MPG calculations and could land you over your 36k mile warranty sooner than necessary.

 

[Idahoktm]

Apologies for the slight sidebar, but what are the pros to getting a calibration done aside from the speedometer being accurate again? Im aiming to do 35s if that changes anything

With 35's, your speedometer will be off by 5-6 MPH and it's a PITA trying to remember that you are going faster than your speedo indicates. If you like to drive 5 MPH over the speed limit, you might forget and be 10-11 over and get busted easier. Some claim that the shift points aren't correct if you don't recalibrate. Your fuel computer won't be accurate. It's actually a benefit if you don't get it recalibrated, as far as your warranty goes, because you will be logging less miles with the bigger tires than you actually traveled.

 

[Av1]

Just as a reminder, and I'm sure most already know, input your tire's rolling diameter NOT the overall diameter of the tire.

Measure center of hub to ground with tire installed and multiply times 2. Don't measure from the ground to the top of the tire.

The rolling diameter is always significantly less than overall diameter, but it is the accurate way to do it.

 

[WXman]

Just as a reminder, and I'm sure most already know, input your tire's rolling diameter NOT the overall diameter of the tire.

Measure center of hub to ground with tire installed and multiply times 2. Don't measure from the ground to the top of the tire.

The rolling diameter is always significantly less than overall diameter, but it is the accurate way to do it.

The way I've done it using the Tazer is I set a level on the top of the tire while the tire is mounted on the truck. Then I measure in a straight line from the ground to the bottom edge of the level. This is the exact tire height. I then set the Tazer menu to this exact height. With GPS I'm always spot-on the money. Done this on 4 different vehicles with this same Tazer and it's always perfect.

Obviously if a guy is using Alfa or some other way to adjust the steps may be different like you were saying. Revolutions instead of diameter.

 

[Eighty]

The way I've done it using the Tazer is I set a level on the top of the tire while the tire is mounted on the truck. Then I measure in a straight line from the ground to the bottom edge of the level. This is the exact tire height. I then set the Tazer menu to this exact height. With GPS I'm always spot-on the money. Done this on 4 different vehicles with this same Tazer and it's always perfect.

Obviously if a guy is using Alfa or some other way to adjust the steps may be different like you were saying. Revolutions instead of diameter.

I’m surprised that this method ends up being 100% accurate. By doing that, you’re capturing the “squish” of the tire at the bottom, but the top doesn’t compress. I would think the measuring center of wheel hub to ground (and multiplying by 2) would be the most accurate. That’s what the vehicle actually sees as a full rotation.

 

[moosem]

All I did was take the theoretical diameter and subtracted 3%. It was perfect first try. Probably just got lucky though!

 

[Av1]

The way I've done it using the Tazer is I set a level on the top of the tire while the tire is mounted on the truck. Then I measure in a straight line from the ground to the bottom edge of the level. This is the exact tire height. I then set the Tazer menu to this exact height. With GPS I'm always spot-on the money. Done this on 4 different vehicles with this same Tazer and it's always perfect.

Obviously if a guy is using Alfa or some other way to adjust the steps may be different like you were saying. Revolutions instead of diameter.

If you're always spot on with your GPS, you're good to go.

The most important thing is that it's accurate, not how you got there.

 

[VectorZ]

If you're always spot on with your GPS, you're good to go.

The most important thing is that it's accurate, not how you got there.

For me, I just use a free GPS speedometer app and tweak the tire size once or twice to get it exact.

 

[lawmann8]

For me, I just use a free GPS speedometer app and tweak the tire size once or twice to get it exact.

That's what I did as well. Worked perfectly.

 

[PurpleRT]

Thats what I did as well.


Sent from my iPhone using Tapatalk Pro

 

[lawmann8]

Great minds think alike!

 

[Chrysler Factory Warranty]

I have a 2021 1500 Limited. 2 weeks ago I had Discount Tire replace my stock 285/45r22 for 285/55r22 Recon Grapplers. As such, my speedometer is off by about 6 MPH at 60MPH. I have read on this board many went to their dealer for $125-$150 and had the speedometer adjusted so I set an appointment. I went today and service rep came back and said to "get the codes" Chrysler wanted me to "subscribe" to larger tires at a cost of $350. What the hell is this? Needles to say I did not pay and left.

I am pretty sure the dealer pays between 100-150 right to Mopar for this calibration. I do know there are other good alternatives for about the same money. The other alternatives give you the flexibility of changing it again in the future. One down side is the aftermarket programmer may effect your Warranty/Extended Warranty coverage.
Hope this helps.


Hope this helps. Also if you are considering a Mopar Warranty, here is a good article wrote by one of my colleagues. Is A Mopar Extended Warranty Worth It?

 

[TyH2009]

I just went to the dealer to have mine reflashed yesterday. Took an hour and a half to run the reprogram they said and they charged me an hour and a half labor, $199 an hour, so $300, what a freaking ripoff.