Innovative Euro VI technology platform provides an outlook on the new 2014 generation of Unimogs

  • New engines: environmentally friendly, powerful and economical
  • Emission control combines SCR technology and particulate filter
  • Performance improved yet again
  • Increased payload due to a weight-optimised design and an increase in load ratings
  • Compact thanks to smart arrangement of components

unimog iaa commercial vehicle show

Mercedes‑Benz Special Trucks has provided an initial outlook on the future of the Unimog in its role as a technology platform and has demonstrated the future drive train compliant with the Euro VI emissions standard using a compact chassis which is based on the medium U 400 model series.

Thanks to its versatility, the equipment carrier is often used in environmentally sensitive areas. In addition to the drive, Mercedes‑Benz uses the technology platform to provide an initial indication of extensive further developments to the Unimog of the future as well as its compact dimensions. These will be implemented in large-scale production during the coming year.

New generation of engines: environmentally friendly and economical

In a step towards the Euro VI standard, the Unimog has been equipped with the new OM 934/936 generation of engines with four and six cylinders and a displacement of 5.1 l or 7.7 l subsumed under the term BlueEfficiency Power. These engines are characterised by environmental friendliness, low exhaust emissions, an extremely high degree of economy thanks to a long life cycle, low consumption of fuel, AdBlue and engine oil, as well as long maintenance intervals.

Numerous technical refinements

The appeal of these engines lies in a feast of technical features. A crossflow cylinder head with four valves per cylinder guarantees a fast gas exchange. The cylinder head and the crank case are connected by six screws per cylinder. This provides for an extremely rigid and thus strong connection. The two overhead camshafts operating the valves of each cylinder are constructed and formed from a hollow shaft with shrink-fitted cams. This design is both light and robust.

The refinements to the new OM 936 include the VCP (Variable Camshaft Phaser). The term refers to a variable exhaust camshaft, the first camshaft of its kind in a diesel engine. Its adjustment supports the regeneration of the particulate filter. If regeneration is necessary, the valve timings are adjusted in order to increase the temperature in the exhaust duct.

Emission control combines SCR technology and particulate filter

With regard to exhaust gas aftertreatment, both engines rely on the BlueTec‑6 technology from Mercedes‑Benz: a sealed particulate filter together with the SCR system used by Mercedes‑Benz for many years complement each other perfectly. BlueTec‑6 technology reduces particle emissions to a level almost beyond detection and the nitrogen oxide emissions are broken down into harmless air constituents by the injection of AdBlue in the downstream SCR catalytic converter.

The new engines impress with immediate acceleration and outstanding performance in conjunction with excellent smooth-running. High torque at extremely low engine speeds ensures a superior and economical power delivery just above idling speed. This is an important factor for operations in which these equipment carriers are typically involved, where great tractive force and endurance are a central issue.

Performance improved yet again

The Unimog of tomorrow profits from the downsized highly-efficient engines: the four-cylinder OM 934 achieves the same performance as previous six-cylinder engines. It is built into the technology platform.

The new engines will also contribute towards further increasing the Unimog’s performance. For the first time ever the Unimog achieves 220 kW (229 hp) thanks to the six-cylinder engines. The engine power of the all-wheel-drive equipment carrier is transmitted by means of the well-known Unimog transmissions. Like the portal axles, these have also been reinforced for the increased engine torques of up to 1200 Nm. In addition, the weight-optimised design and an increase in load ratings have also increased the payload in comparison to the current model.

New vehicle components such as the diesel particulate filter and more powerful engines with larger cooling systems go hand in hand with an increased unladen weight. To counteract this, the Unimog developers have implemented a weight-optimised design without forfeiting any of the Unimog’s legendary stability and robustness. This has been achieved by apertures in the frame and the use of aluminium wheels. The light alloy wheels have already proved their value on construction sites and municipal operations. The vehicle’s permissible gross vehicle weight has been increased moderately, in order to maintain the load capacity.

Smart arrangement of components increases compactness

The developers have also used the new component package to compensate for the larger volume of the Euro-VI-compliant components, notably caused by the large cooling system and the additional particulate filter. The cooling process is divided between several components in two locations on the chassis. Amongst other things, an optimal airflow around the engine provides the larger volume of cooling air required by engines compliant with the Euro VI emissions standard. An important feature of the new cooling concept will also be the ease of maintenance.

The wheelbase of the Unimog will actually be eight centimetres smaller than the current model.

A glimpse of the future

Despite the greater dimensions of the design made necessary by the legal requirements of the Euro VI standard, the Unimog maintains its compactness; one of its most important unique selling points.

The new generation is more environmentally friendly and more economical. When launched onto the market its product characteristics with regard to performance, user-friendliness, drive, ergonomics and safety will have been completely revised.