tire size vs speedo error

[distorted]

i just did a three inch body lift to clear the new 33" tires, wut do i have to do to have an accurate speedo reading?

 

[FROADER]

Try this.

http://www.explorer4x4.com/speedo.html

 

[distorted]

thanx froader...guess this means pulling the gear counting teeth n figuring the actual reading error