In a hybrid vehicle equipped with an engine and a motor that are connected
to a driveshaft linked to an axle via a gear mechanism, on condition that
a torque demand Tr* required for the driveshaft is lower than a preset
reference torque level Tref (step S220) and that a vehicle speed V is
lower than a preset reference speed level Vref (step S230), the drive
control of the invention idles the engine (step S240) regardless of a
stop request of the engine (steps S120 and S210). This arrangement
effectively reduces the potential for backlash or gear rattle in the gear
mechanism. On condition that the vehicle speed V is not lower than the
preset reference speed level Vref (step S220), on the other hand, the
drive control of the invention stops the operation of the engine (step
S250) in response to the stop request of the engine (steps S120 and S210)
even under the torque demand Tr* of lower than the preset reference
torque level Tref (step S230). This arrangement desirably enhances the
energy efficiency of the hybrid vehicle.