Unsprung weight in relation to thrust only effects motive force via it be a component of the total vehicle weight, is a major component in determining the tractive potential of the vehicle. Unsprung weight in primarily a measure used in working through vehicle dynamic (raide and drive) equations as opposed to drivetrain performance equations.
Out of curiousity, where did unsprung mass come into all of this? Did I miss something? If this was being used in the Nitrogen vs. air arguement, you would be better off watching the tire guy so that he puts the least amount of bead soap on the tire possible while mounting it. That would make the tire comparatively alot lighter than filling the tire with Nitrogen. :geek: