Torque calculation method for engine

An ECU executes a program including a step (S106) of setting a time constant T that is used in a smoothing process for actual indicated engine torque to a large time constant T(1), when a change amount A of ignition timing is large ("YES" in step S104); a step (S110) of calculating an output value TS by the smoothing process for the actual indicated engine torque; a step (S114) of performing a subtraction process for the output value TS according to the number of cylinders for which fuel cut is being performed when fuel cut is being performed ("YES" in step S112); a step (S118) of calculating actual net engine torque by subtracting friction torque, pumping loss, load torque of auxiliary machinery, and an idling torque deviation learning value from the output value TS; and a step (S124) of correcting the actual net engine torque so that the actual net engine torque is increased according to a temperature of lubricant.