This paper presents an efficient-improved modulation and control approach referring to the interleaved boost with coupled inductors (IBCI) dc-dc converter topology. Pulse-width modulation approaches for this converter allow various degrees of freedom, which should be exploited in order to minimize conduction and switching losses. Favorable switching sequences are identified deriving a modulation scheme that allows significant efficiency improvements as compared to classical modulation approaches. It is shown that the achieved efficiency performance is close to the optimal one found by a brute force characterization of the prototype. Finally, the obtained modulation scheme is integrated into a closed-loop control of the converter's power flow, achieving low power losses also during non steady-state conditions. Three different implementation techniques are discussed and compared.