Beyond Efficiency: A Unified Energy Survival Law for Road, Freight, and Marine Transportation

Classical energy efficiency metrics systematically overestimate real-world performance acrosstransportation, biological, and engineered systems. This discrepancy arises because efficiencyisolates individual components under idealized conditions, while real systems operate throughsequential absorption, transport, conversion, regulation, and dissipation stages, each subject toirreversible entropy production.This study introduces a Unified Energy Survival–Absorption–Conversion Law, replacingefficiency with a physically grounded energy survival factor (Ψ) that explicitly accounts forirreversible thermodynamic losses. The survival factor is defined asΨ = 𝐴𝐸/𝑇𝐸 + 𝜀 , 0 < Ψ < 1where AE is absorbed energy, TE represents recoverable transport and thermodynamic losses,and ε denotes irreversible entropy-generating losses.To capture finite throughput and rate constraints, an internal conversion competency term(C_{int}) is introduced. The resulting governing law for useful energy production becomes:𝐸𝑢𝑠𝑒𝑓𝑢𝑙 = 𝐸𝑖𝑛 ⋅ Ψ ⋅ 𝐶𝑖𝑛𝑡Applied to electric vehicles, internal combustion vehicles, marine propulsion, and rail transport,the framework accurately predicts observed field-scale performance envelopes: ~60–75%wheel-level energy delivery in electric vehicles, ~20–30% in internal combustion transport, and~40–55% shaft-to-thrust efficiency in marine systems.By explicitly modeling energy survival rather than idealized conversion, the proposed lawresolves long-standing efficiency paradoxes, enables cross-modal comparison, identifiesdominant loss stages, and establishes hard thermodynamic upper bounds on transportationperformance. Please check the attachment for details