Weight vs Torque relation

I am trying to figure out the torque vs weight relationship. I am working on a software project where I want to create an application to determine the maximum payload on vehicle with rubber tyre on asphalt road.

I am having three parameter

1. Torque
2. RPM
3. Diameter of tyre

based on which I need to determine the payload capacity of a vehicle.

Example 1

Torque = 106 kg.cm
RPM = 10
wheel diameter = 10 cm
Speed will be = 2 X pi X (diameter/2) X (RPM/60) = 5.24 cm/s

Example 2
Torque = 47.19kg.cm
RPM = 200
wheel diameter = 5 cm
Speed will be = 2 X pi X (diameter/2) X (RPM/60) = 52.38 cm/s

Example 3
Torque = 109.20 kg.cm
RPM = 60
wheel diameter = 6 cm
Speed will be = 2 X pi X (diameter/2) X (RPM/60) = 18.86 cm/s