The transport sector requires compact, reliable, and energy-efficient power units for mod ernization of road, rail, maritime, and aerial systems. Conventional piston and rotary ma chines often face limitations related to vibration, sealing losses, and manufacturing com plexity. This study investigates birotor machines (BM), a class of positive-displacement devices combining synchronized rotation of the rotor and housing. This configuration en sures smooth kinematics, near-complete dynamic balance, and simplified design. The working principle enables continuous volumetric transformation with reduced friction and leakage, enhancing efficiency and durability. Using generalized mathematical models (GMM) developed through statistical experimental design, optimal geometric parameters were determined with a root-mean-square error below 3%. A prototype birotor compres sor (BC) designed for subway rolling stock achieved equivalent output performance (0.43 m3/min at 0.8 MPa) with 82% efficiency and a mass reduction from 130 kg to 32 kg. Com parative simulations and preliminary testing of BM-based internal combustion engines (BRICE) demonstrated 3–4 times smaller and lighter units with improved reliability and environmental characteristics. The results confirm that BM technology provides a feasible and manufacturable alternative to conventional designs, suitable for integration into next generation transport and unmanned vehicle systems.