A control method for a hybrid vehicle which includes an engine, a first
motor/generator, a second motor/generator, and a manual changing device
that changes a driven state of an output member of the engine that
depends on a driving state of the engine and a driving state of the
second motor/generator, includes the steps of detecting required driving
force of the vehicle; detecting required output torque of the second
motor/generator based on the required driving force when a change in a
rotational speed of the engine is detected; comparing the detected
required torque to the maximum permissible torque of the second
motor/generator, and increasing a gear ratio when it is determined that
the required output torque is greater than the maximum permissible
torque.