Ran a search on Speedometer calibration, couldn't find anything where someone actually had their speedo reset to compensate for larger tires. Don't think it's necessary when going to 285's (wasn't on my '01) but if a change to 35's is made, it would be a good idea. Any thoughts?

A friend who owns a Ram told me the dealer can set the speedometer on those trucks by entering the number of revolutions per mile into the trucks computer.

Also, what is the backspacing on the factory 17" and 18" 4x4 wheels?

Thanks guys!

 

Hi Zach,
Just a thought on recalibrating speedo for different size tires. I know they arent out yet, but when they are released most of the "tuners" have been capable of doing this for you. Not the chips but the plug in type where you dictate what changes you want to make. If you ever want to go back to original setting you can do that too.

Wish I had known you wanted the backspacing measurement when I had my wheels off the other day and I would have measured it for you. If you dont find out through normal channels soon, let me know and Ill pop one off and measure it for you. Mine are the 17" wheels.

 

Can't remember where I got this info but I wrote down +44mm in my F150 brochure.

 

BTW that's the factory wheel offset measurement, not the backspacing.