A vehicle is provided with an engine (1), an automatic transmission (2)
connected to the engine (1), a detection device (21-24, 31) which
detects an operating state of the transmission (2), and a torque regulating
mechanism (1a, 1b, 1c) which regulates
a torque of the engine. When the operating state of the transmission (2)
is in a predetermined drive state and the torque of the engine (1) is to
be reduced, a selection is made, based on the operating state of the transmission
(2), between a first torque reduction control whereby the torque of the
engine (1) is reduced rapidly and temporarily, and a second torque reduction
control whereby the torque of the engine (1) is reduced continuously, and
more smoothly than in the first torque reduction control. The torque of the engine
(1) is then reduced by the selected one of the first torque reduction control
and the second torque reduction control.