More comfort features added to each berth has charging point, AC control vent, better design staircase, dual tone upholstery with toned finish. On the other side the berth width and gap in each compartment is reduced by 1-2 inch and AC unit shifted to coach bottom to accomodate one more room and a 3 berth room to increase seating capacity from 72 to 83. The fare difference between 3AC and economy 3AC is 8% cheaper.