Sequential Manual Gearbox: Introduction

The sequential manual transmission (SMG) has its origins in motor racing and has in time been modified for use in series production.

In detail, SMG means that in contrast to a conventional manual transmission, the clutch control and gear change are automated. An electrohydraulic control system takes over the clutch operation and gearshifts.

The SMG can be driven in manual mode or in automatic mode, as follows:

• Manual mode: sequential, manual gearshifts

Gears are selected in sequence (sequentially) by briefly pressing "+ or "-". Gears can be skipped by rapidly pressing the button repeatedly.

Gears are changed by one of the following means:

• Gear lever in the center console, or
• 2 gearshift paddles on the steering wheel.

The shift pulse is transmitted electrically to the SMG control unit. With this gearshift method ("shift-by-wire") there is no mechanical linkage between the gear lever or gearshift paddles and the transmission.

• Automatic mode = D:

In automatic mode, the shift points are automatically controlled according to characteristic curves and are adapted to the driving situation.

The SMG is available as special equipment (option 206).

So as to be compatible with higher-torque engines, the SMG are designed with different power ratings. The SMGs therefore differ, for example, in terms of more powerful clutch actuators.

The following SMGs are installed depending on the motorization:

The SMGs are based on the 6-speed manual transmissions GS6-53BZ and GS6-37BZ.

The principal benefits of the SMG compared to a conventional manual transmission:

• No clutch pedal as the clutch is operated automatically
• Selection of 4 operating modes:
  • Manual mode

    Sequential, manual gearshift via gear lever or gearshift paddles

  • Manual mode with Dynamic Driving Control (FDC) via SPORT button

    Sporty driving style by power steering being adapted (only with Servotronic) and intervention in engine and transmission control

  • Automatic mode = D ("Drive")
  • Automatic mode with Dynamic Driving Control (FDC) via SPORT button

    Sporty driving style by power steering being adapted (only with Servotronic) and intervention in engine and transmission control

• Short and precise gearshifts, no incorrect gearshifts possible (gear change in approx. 0.15 seconds)
• Safety and comfort: because the gearshift paddles are on the steering wheel, you can keep your hands on the steering wheel when you change gear.