The ON&OFFROAD package for the new M-Class uses six different driving modes to optimise driving dynamics and handling safety by providing the optimum drive control needed to cope with the wide spectrum of operating conditions encountered both on and off the road. The added benefit compared to the Off-Road Pro Engineering package offered previously is plain to see: whereas before there was one optimum driving mode for the road and one for off-road, drivers now have the choice of an automatic mode, as well as two specially programmed off-road and three on-road modes.

The specific driving modes for all-wheel drive resolve a conflict of objectives that has previously hampered further development of 4MATIC and the 4ETS electronic traction system as well as ESP® and ASR. To take an example: on off-road tracks, it is important that the control systems respond very gently due to the low friction coefficients, but this makes a sporty setup virtually impossible. Conversely, a sporty basic setup impairs performance abilities in off-road terrain. In the past, the engineers always succeeded in finding excellent compromises which worked brilliantly under all conditions and continue to do so. The new ON&OFFROAD package with its specific driving modes, however, enables driving dynamics and handling safety to be optimised almost as far as is physically possible under all operating conditions by maximising networking between the individual control systems.

The system is operated using a rotary control on the centre console, which adapts the AIRMATIC settings and the drivetrain to suit the specific requirements. The six driving modes in detail:

Automatic - covers the wide operating spectrum of everyday driving
Offroad 1 - light terrain, tracks, driving over fields
Offroad 2 - challenging off-road terrain with climbs
Winter - for driving in wintry conditions on roads affected by freezing rain, snow or ice, or with snow chains
Sport - for serious driving along winding roads
Trailer - optimises start-off, manoeuvring and braking characteristics when towing a trailer

Despite so many options, the driver is never in any doubt about mode selection: the setting is made intuitively, while the driving mode selected is visualised in the multifunction display as well as in virtually photo-realistic quality on the screen of the COMAND system. If the driver selects the Winter mode, for instance, the display shows the M-Class in snow. The Sport setting displays a racetrack with red-and-white curbs, while images of off-road terrain with different profiles appear for Offroad 1 and 2. The display is interactive too: steering input and spring travel correspond to the actual values, while the graphics include additional information on the steering, gradient and tilt angles, the AIRMATIC level, the pre-selected speed for Downhill Speed Regulation (DSR), as well as the selected drivetrain settings including reduction gear and differential lock.

Irrespective of which basic mode is set, the reduction gear, differential lock, DSR and the AIRMATIC system's level control can all be adjusted individually. As with the basic settings for the ON&OFFROAD package, it is not possible for the driver to make mistakes here either. Illogical settings, which would have a negative impact on handling stability, safety or traction, are precluded. If case of doubt, the system will revert to automatic mode.

In terms of "hardware", the ON&OFFROAD package comprises an underguard, a two-stage transfer case with reduction gear, an inter-axle differential lock and enhanced AIRMATIC functionality that allows a maximum ground clearance of 285 millimetres and a fording depth of 600 millimetres.