In some vehicles, it is possible to use a control unit to electrically operate the clutch if the vehicle is equipped with an automated transmission or an enhanced transmission. In an overrun mode, the clutch between the engine and transmission is engaged, which brakes the vehicle due to the compressor action of the engine and friction. In addition, free-wheel transmissions are believed to be conventional which do not have this disadvantage since they transmit the engine torque only in driving mode, but do not transmit the engine braking torque in overrun mode. However, the vehicle must always be decelerated by the vehicle brake, which can overheat, in particular, during long downhill travel.
Electronic automatic transmissions that engage a certain gear at the request of a control unit—including “neutral,” in which no engine torque is transmitted—are also believed to be conventional.
In addition, engine start/stop systems which, however, work only while the vehicle is at a standstill, are believed to be conventional.