An elevator system (20) includes a propulsion power assembly (38) with a power rating below that required to move a fully loaded elevator car (22) using a contract or design motion profile. One example propulsion power assembly (38) uses more than one motion profile based upon existing load conditions. One example uses a first motion profile including a first power parameter limit for load conditions at or below a selected load threshold that is less than a maximum load capacity of the car (22). The propulsion power assembly (38) uses a second motion profile with a lower power parameter limit for other load conditions. In one example, electrical current is the power parameter selected as a decision parameter dictating which profile to select based on an existing load. Another example propulsion power assembly (38) selects at least one of a speed limit or an electrical current limit based on an existing load and maintains a speed to stay within the selected limit.