Abstract: A method for controlling a clutch of an automatic transmission for improvement of fuel efficiency may include determining whether external driving conditions of a vehicle meets coasting conditions, determining a clutch slip control time and an amount of clutch slip torque according to internal driving conditions of the vehicle, performing slip control on a clutch that works at each step of the automatic transmission using the determined clutch slip control time and torque, wherein an engine brake torque transmitted to a final output shaft of the automatic transmission may be reduced.

Abstract: An input shaft damper (ISD) of a transmission, may include an inertia body assembly relatively rotatably mounted on an input shaft of the transmission, and a planetary gear set mounted on the input shaft so as to receive and increase a rotational force of the input shaft and output an increased rotational force to the inertial body assembly.