It is neither sleek in design nor fast in speed, yet the Mercedes-Benz Unimog is among one of the most recognizable road, or in its case, off-road, vehicles. A flagship in any military logistic fleet and headliner to humanitarian relief efforts worldwide, the versatile 4x4 truck has just gotten better with the introduction of the U4023 & U5023 models. With a product range now up to ten different editions, the new Unimog features a new set of LED headlights, improved daytime running lights, and a front-mounted camera monitor. With the re-positioning of the engine further back into the cab, the interior space widens to provide more room. The newly arranged cab also gives a panoramic view to the driver in addition to the new air conditioning system, steering wheel column, and dashboard.
Another important change is the powerplant specifications. Now compliant with the strict Euro VI emission standard, the four or six-cylinder Mercedes BlueEfficiency Power engines can produce from 156 horsepower all the way to 354 horsepower. And did we mention its ability to climb a 45-degree slope angle and 34-degree ramp angle, a side tilt of 38 degrees, plus a tire inflation system? All of this makes the Unimog as extreme as they come in the world of off-road trucking.
Unimog U 4023 and U 5023: Setting standards for off-road mobility
Perfection off-road, better handling with centrally-positioned engine
New BlueEfficiency Power Euro VI engines with higher output and higher torque
Chassis concept with torsionally flexible frame, torque tubes and coil springs retained
Strong and reliable, many details improved
New engine power take-off with increased applications
The outstandingly mobile off-road Unimog with its new reference numbers U 4023 and U 5023 as the follow-up models for the U 4000 and U 5000 is now more environmentally acceptable and efficient, but still just as mobile off the road as its predecessors and even stronger – that means better all round. It is fitted with the new four-cylinder BlueEfficiency Power BlueTec 6 engine with an output of 170 kW (230 hp) and a strong torque of 900 Nm. The Unimog transmission has been improved and uprated so that the gear changing times are shorter with an increased life span. In future the gears will be changed using the pitman arm on the steering column and this also includes the electronic quick reverse function (EQR). As up to now, there are eight forward and six reverse gears available as well as the optional crawler gears for off-road use with a speed range between 2.5-35 km/h. The main difference between the two big Unimog vehicles lies in their axles and frames i.e. their axle loads and the gross vehicle weights which is a maximum of 10.3 tonnes for the U 4023 and 14.5 tonnes for the U 5023.
Time-tried cab with a short bonnet radically reworked
This cab is first class – it has left its mark on the appearance of the outstandingly mobile off-road Unimog since 1974. The designing engineers were confronted with the challenging task of installing technology complying with Euro VI and they succeeded by repositioning the engine one metre further back under the cab and this is now the core of the new concept. In comparison with its predecessor, the new cab has been lengthened by 120 mm and is slightly higher – and by moving the transmission controls from the central console to the pitman arm on the steering column there is much more space in the interior of the cab.
This cab has also been upgraded with its new fittings: The multifunction steering wheel, adjustable steering column, pitman arm control, multifunction touch-keys and instrument cluster with a large display as well as a new stronger heating and ventilation system provide the very best conditions for the driver. The central tire inflation system "Tirecontrol Plus" has been redesigned so that the correct tire pressure for the prevailing conditions can be chosen simply and easily in the display with the pre-programmed modes "road", "sand" and "bad surface". From the outside the dynamic design of the radiator and the new bumpers with modern headlamps show at the first glance that here there is a new generation of the Unimog on the job. Also the access to the cab is completely new with easy to master and safe steps, two or three depending on what the customer requires. The altered position of the engine also allows power to be taken directly from the engine with an engine-driven PTO so that implements can be run independently of the driving situation unlike the transmission-driven PTOs which are still available.
Perfect for off-road operations
The big advantages of the extremely mobile off-road Unimog such as its outstanding handling over tough terrain remain untouched and in individual points its strengths have been improved. In the new model, the curving of the frame is now further back due to the central position of the engine and altogether the Unimog has a lower centre of gravity while retaining its high ground clearance which is extremely important for off-road operations. As both frame and tubular cross members are welded, this guarantees the extremely good torsional flexibility of up to 600 mm when driving cross-country. The axle articulation of up to 30° is made possible by the torque tube technology combined with the coil springs by connecting the torque tube and the torque ball to the transmission. Portal axles, the low centre of gravity and extremely good angles of approach and departure (at the front 44°, at the rear 51°), and ramp angles (34°) as well as its slope climbing ability (45°) all go to make the outstandingly mobile off-road Unimog just what it is – and in addition there is its fording ability of a maximum of 1200 mm as well as its side tilting angle of 38°. Driving in extreme situations is supported by the engageable all-wheel drive, engageable differential locks and the central tire inflation system.
Unimog vehicles have a long life and they are robust and reliable. The completely welded frame and the enclosed parts of the chassis stand for the claim that the vehicle is able to stand up to great stress and strain. The axles are reinforced, all important power units and equipment are metal clad or installed in safe positions – and this is also true for fording ability within the guaranteed depth of 1200 mm.
Extreme operations the world over
All this shows quite clearly just why the outstandingly mobile off-road Unimog has such an excellent reputation all over the world. Working in extreme off-road conditions is the order of the day, whether it is fighting forest fires, for disaster control, crane operations, pipeline construction, expeditions, rescuing man and machine and last but not least for transporting crews and other people – in remote areas where the roads turn into bad tracks and rough terrain, that is where the Unimog U 4023 and U 5023 are on home ground.
The Unimog is also looked after perfectly as far as maintenance, trouble diagnosis or repairs are concerned as competent Unimog Dealers are there to take care of the vehicles in over 650 service stations in more than 130 countries where special service packages and financial services round off the customer care.