A vehicle includes an automatic transmission and a set of sensor inputs providing values indicating a current operational status of the vehicle pertinent to controlling the automatic transmission. The set of sensor inputs include: engine speed, engine torque, current transmission gear; and vehicle speed. The vehicle includes a programmed processor configured to iteratively and co-dependently generate a vehicle mass parameter value and a grade of incline parameter value. The programmed processor, when generating the vehicle mass parameter value and the grade of incline parameter value, uses a set of parameters including: a propulsive force driving the vehicle; a set of forces acting on the vehicle resisting forward movement, and an observed rate of change of a speed of the vehicle.