I currently have 11R22.5 tires on my 2022 Western Star 5700XE. I’m going to swap to 295/75R22.5. How much will my speedometer be off? Can a dealer change the settings on the ECM to correct the speedometer?
Vehicle Speed Calculator It'll vary a little depending on specs and speed, but around 2-4mph. Yes dealer should be able to help.
Depends on the diameter if there is not much difference you'll find it will hardly make a difference. I would not worry to much about it. As the police will usually allow most vehicles a certain percentage over the speed limit anyway.
My speedometer was 3mph off with the smaller tires. Updated the ECM to 509 revaluations per mile. Problem solved.
