Bigger Tires and Calibrating Speedo w IID

[TrinidadLR4]

So now that I run 275 55 20s, I would love it if the speedometer wasn't showing 75mph when I am really doing 80, especially since 80 will get you a reckless driving citation in a state not too far away. I have the IID tool and found a section in the ccf file edits where you can set the tire size and rolling circumference. It won't let me select the proper circumference for these tires(2546mm) as it is not a selection in the list, but I set the tire size, which had no effect. Does anyone know the proper way to set the speedometer to correspond to the new tire size? Maybe I'm doing it all wrong. Thanks!

 

[CaliDisco]

I would think an independent shop could help recalibrate...

Separate but related: how is the larger size working? Rubbing is negligible? Have any issues with loading the spare or TPMS?

I’m very curious as I’d like to go for a 32” diameter tire on mine and just want to know what to expect...
Thanks for posting the process you went through with yours!

Cheers!

 

[TrinidadLR4]

Haven't put the spare on yet - have a 20in rim but need a cheap tire to mount. So far it has been great. Light rubbing under tight low speed turns but that's it. I disabled TPMS completely using my IID tool. Truck feels great and high speed driving/handling is very stable and responsive. Anything else let me know. Very happy with the way it turned out.

Sent from my HD1905 using Tapatalk