A drive system for a mobile machine is disclosed. The drive system may have a travel speed sensor, at least one traction device speed sensor, and a controller in communication with the travel speed sensor and the at least one traction device speed sensor. The controller may be configured to determine a slip value associated with a traction device of the mobile machine based on signals generated by the travel speed sensor and the at least one traction device speed sensor, and determine a torque output value of the mobile machine. The control may also be configured to make a comparison of the slip value and the torque output value with a pull-slip curve stored in memory, and selectively update the pull-slip curve based on the comparison.