original_query: What equipment is included in the chassis of the vehicle?
query: What equipment is included in the chassis of the PT-91 Twardy?
answer: The chassis of the PT-91 Twardy includes a more powerful 850 hp S-12U diesel engine (later variants have a 1000 hp S-1000 engine), a modernized fuel and air injection system, and  the US-DK-1 control and diagnostic complex which controls main systems and displays information on a monitor.  Later variants also include an auxiliary power generator (APU), air conditioning, a new steering system with shuttlecock and day/night reversing camera PCO KDN-1 Nyks, reinforced suspension (torsion shafts, shock absorbers, and elastomer bumpers), and rubber track overlays.