Running larger tires on 2015 Ram 1500

[Sturmgewehr792]

I am considering replacing the stock 275-60R20 tires with 35x12.5R18 A/Ts. The truck has the 3.92 rear end so i am not too worried about gearing.


Does anybody have a method to re-calibrate the speedometer for larger tires?
Also will this void any warranty's for the drive-train with Chrysler?

Thanks in advance.

 

[chipmaker]

I put 35s on my stock 20's. The speedo deviation is negligible. So I have no answer to your question...

 

[Thatdude596]

buy a trinity or various programmers or you can just buy the hyper tech or pro comp speedo recalibration device

 

[DRkNESS]

^^^. As stated above, good luck with it all.

 

[blackbeautyhemi]

Or you can take it to a dealership and they can change it to.

 

[Thatdude596]

Or you can take it to a dealership and they can change it to.

not sure about that one, never have heard that before..you know this for a fact

 

[blackbeautyhemi]

not sure about that one, never have heard that before..you know this for a fact

Yea both of my trucks I did at the dealership my dad works at and his cousin just had his done in there to. Just find the revolutions per mile for your tire and they can program it.

 

[RamRod1371]

2015 or newer you have to buy and Upgraded (diablosport) PCM $600 to calibrate with a trinity. There is also the option to send them your stock PCM and the will flash it for $200. But who wants to be stuck without a truck while they wait. I've been looking for a good solution to this as well, i've had my trinity for a few years and used it on multiple vehicles.
Ive also read that dealerships cant calibrate for tires taller than 33"

 

[blackbeautyhemi]

I had 37's on my old truck and they did it. They also did my 35's and my cousins 35's on his 2012. Only takes a few minutes to be done.

 

[AustinB]

I went to 35s and my speedo is still accurate according to my garmin gps.

 

[blackbeautyhemi]

Mine was only off 3 mph but still wanted it corrected