Safe, clean and economical: "The future begins today" – the motto for the IAA Frankfurt 2011 also applies to modern-day high-tech trucks

Safer, cleaner and more economical than ever before, heavy-duty trucks today are fully fledged high-tech vehicles. Assistance systems maintain a constant safety distance, warn the driver when the vehicle threatens to leave its lane or even initiate emergency braking in case of danger. Engines with fascinating performance capabilities and featuring fully automated transmissions with twelve gears are perfectly matched to produce record-breaking fuel efficiency: long-haul semi-trailer/tractor combinations are now approaching fuel consumption levels in the order of 1 litre to 100 km per ton of payload. New emission control systems combine particle filter, exhaust gas recirculation and SCR system to minimise emissions. The motto for the Frankfurt International Motor Show – "The future begins today" – describes the current generation of trucks perfectly, with the new Mercedes-Benz Actros in the vanguard.


Assistance systems: a host of safety features on board

Drivers covering around 150,000 km a year – the common mileage for a truck on long-haul operations in Europe – have to deal with their fair share of tricky situations. And drivers moving 40 tons along the roads have a special responsibility. Against this background, diverse assistance systems are available for modern-day heavy-duty trucks, to support the driver in going about his responsible daily work. Assistance systems maintain a constant safety distance, adapting the vehicle's speed accordingly. They provide a timely warning when the vehicle threatens to leave its lane and prevent semi-trailer/tractor combinations from swerving – a major challenge for the developers in view of the combinations of vehicles involved. The new Mercedes-Benz Actros with Active Brake Assist even initiates emergency braking automatically in the event of danger. Sometimes it is little details that make a big difference: a sensor detects whether the fifth wheel coupling is correctly locked. Sophisticated mirror systems provide for good visibility – including a manoeuvring function with extended field of vision. Some systems are now firmly established standard features for heavy-duty trucks and require no further explanation: ABS anti-lock brake system, acceleration skid control (ASR), the Electronic Brake System (EBS) and internally ventilated disc brakes on all wheels, for example. Maximum safety is in every company's best interest – nothing is more costly to business operations than a truck that is out of service and unable to deliver its load to its destination on time.

High-tech auxiliary brakes rated at up to 750 kW (1020 hp)

While they demand respect, modern-day heavy-duty trucks such as the new Mercedes-Benz Actros need not be feared in any way. They incorporate a wealth of safety features which minimise the risk of an accident. The high-performance disc brakes are supported by a powerful engine brake, for example. At up to 400 kW (544 hp), this brake has a higher power output than the vehicle's engine. This system is commonly also backed up by an auxiliary brake in the form of a hydrodynamic retarder. Retarders attain a vast power output of up to 750 kW (1020 hp).

Emission control: high-tech processing system in the exhaust muffler

The exhaust muffler on a truck of the new generation is much more than a silencer, functioning rather as a compact high-tech laboratory dedicated to the task of emission control. Here too, the new Mercedes-Benz Actros plays a trailblazing role, combining SCR technology with feed-in of AdBlue, cooled exhaust gas recirculation and particulate filter. This extremely efficient emission control system reduces particles, nitrogen oxides and CO2 to a minimum. The new Mercedes-Benz Actros is the first truck to comply with the Euro VI emissions standard. Euro VI will become mandatory for heavy-duty commercial vehicles in 2013/2014, entailing a reduction of around 97 percent in particle emissions and around 95 percent in nitrogen oxides in comparison to Euro I dating from 1992. "If you run this engine (Euro VI) in a city with heavy air pollution, the exhaust gases will be cleaner than the ambient air," explains an expert from Daimler.

Fuel consumption per ton of payload reduced to only 1 litre per 100 km

Environmental friendliness, the conservation of resources and economic efficiency do not constitute conflicting aims for a truck. On the contrary – operators of commercial vehicles have to calculate their costs very keenly, and in addition to cutting costs every litre of fuel saved also helps to protect the environment and resources. Modern-day semi-trailer/tractor combinations with a total weight of 40 tons have long dipped below the 30 litres/100 km mark on many common routes. They are already approach 25 litres to 100 km. To put it another way: in tough everyday operations they run on only 1 litre to 100 km per ton of payload. This has been confirmed by Daimler's "record run" over 10,000 km on the Rotterdam – Szczecin – Rotterdam route. No small car comes anywhere near this figure, even under favourable conditions.

Sophisticated technology is required in order to achieve such fuel economy. Heavy-duty trucks are commonly equipped with engine power in the order of 300 to 375 kW (408 to 510 hp). This power is available well below 2000 rpm, in a rev range where many a passenger-car diesel engine is still contending with turbo lag. The maximum torque of around 2000 to 2500 Nm is even available from just above idling speed, at around 1000 rpm. Thanks to this characteristic, truck engines run in fuel-efficient mode at only around 1300 rpm when travelling at the customary motorway speed of 85 km/h. Asymmetric exhaust gas turbochargers or twin turbochargers are one of the requirements for such vast power output at low revs. The power dimensions are fascinating: highly charged truck engines generally attain specific torque of around 200 Nm per litre of displacement – on a par with the most powerful passenger car engines.

Fuel injection at more than 2000 bar

The combination of power and economy begins in the combustion process: the fuel is injected into the cylinders under high pressure, in some instances well in excess of 2000 bar. This corresponds to around 800 times the standard pressure in a passenger car's tyres. The engine's electronic system calculates the timing and quantity of each diesel injection operation for each individual cylinder with precision in a fraction of a second, by reference to numerous parameters. On cutting-edge trucks, auxiliary units such as the alternator, the air compressor for the brake system, the water pump and even the power steering system operate in particularly economical on-demand mode.

In premium-class heavy-duty trucks the power output is apportioned by fully automated transmissions, usually with twelve forward gears. Thanks to sophisticated data-processing programmes, these transmissions carry out gear-shifting more effectively than even the best drivers. The transmissions are non-synchromesh in design, reducing weight and shift times. A defined portion of double-declutching during downshifting ensures perfect, jolt-free shift quality. Free-wheeling systems utilise the vehicle's momentum, leaving the truck in neutral where appropriate and subsequently engaging the right gear automatically when it is required.

Tested in the wind tunnel: spoilers reduce fuel consumption

In view of a truck's large frontal area and basic cubic form resulting from its maximum dimensions (central Europe: height 4.0 m, width 2.55 m, length of semi-trailer/truck combination 16.5 m), aerodynamics plays a key role in truck design. Against this background, developers put modern-day trucks through intensive wind tunnel testing. The cab itself, as well as its attachments, are optimised step by step in the course of these tests. Rather than serving to create a sporty appearance, a front apron, cab-side extenders and an adjustable air deflector on the roof of a heavy-duty truck provide effective means of reducing fuel consumption, thereby improving the vehicle's economic efficiency as well as its environmental performance.
The web special on the Actros at the 2011 Frankfurt International Motor Show, featuring product information, live images and impressions from the stand, is available online at: www.mercedes-benz.com/actros4iaa .

Source: Daimler AG

Copyright © 2011, Mercedes-Benz-Blog. All rights reserved.

Mercedes-Benz-Blog TRIVIA: The history of modern Mercedes-Benz Concept Vehicles

Concept vehicles have always been an essential piece in the modernization and progress of the Mercedes-Benz brand. Used to highlight the future models and technologies that are to be serially produced in a matter of years, this special type of show car is part of a very complex philosophy developed by the German constructor, which is used to strictly delimitate concept machines from research cars, technology demonstrators, experimental vehicles and design studies.


The modern era brought a wealthy array of spectacular vehicles that announced the next generation of Mercedes-Benz models. The Coupé concept of 1993 previewed the new design identity, dominated by the 4-eyed front fascia, to be then materialized in 1995 on the W 210 generation of the E-Class. Nonetheless, several other advances and features premiered on this model were to become reality on other series-produced cars, such as the fastback tail on the new C-Class sports coupé (CL 203) of 2000 and the panorama glass roof on the E-Class (W 211) of 2002.

The Vision A 93 and the Studie A prototypes that followed later in 1993 and 1994 heralded the first-generation of the A-Class compact MPV in 1998, whereas the MCC (Micro Compact Car), an early-satge project for the city car of the future, paved the way to the smart city coupé (today, the fortwo version).

The innovative SLK I and SLK II concepts that were equipped with an ingenious metal folding roof announced a new compact roadster model in the Mercedes-Benz lineup, placed just below the SL, that came in 1996: the Sport Leicht Kurz or SLK (R 170).

The versatile and activity-oriented AA Vision concept car unveiled in 1996 at the NAIAS Detroit became reality one year later, when the Sttutgart-based carmaker unleashed the M-Class sports utility vehicle, bound to be assembled at the Tuscaloosa plant in Alabama, USA.

Nearing the end of the 20th century, Mercedes-Benz revealed the Maybach ultraluxury limousine study and Vision SLR that led to the official unveiling of the Maybach 57/62 range in 2002 and the SLR McLaren supercar in 2003.

The Vision SLA of 2000 was more of a proposal for a new, possible small-sized open-top in the Mercedes-Benz portfolio, placed below the SLK. It never hit streets as a series model, but lately, hints are the concept is back on the decision table. If the answer is unanimously positive, chances are the future SLA could arrive in showrooms after 2013.

At the IAA Frankfurt 2003, Mercedes-Benz shocked the audience with the unveiling of an astonishing prototype, which harmoniously blended the sexy lines of a 2-door model into a 4-door limousine: the Vision CLS. The car was very well-received and the decision to send it into the market quickly came into force. And that's how the first CLS-Class was born in 2004.

The sports tourers segment began shaping up when Mercedes-Benz released the 2002 Vision GST, 2004 Vision GST II, 2004 Vision R and 2004 Vision B (CST). This family-oriented, roomy yet dynamic and appealing set of show cars teased the new R-Class and B-Class models premiered in late 2004 and 2005.

The outrageous Maybach Exelero prototype of 2005, used for high-performance Fulda tyres, and the nonconformist 4-door luxury cabriolet Ocean Drive Concept of 2007 never reached series production, but some of the new technologies systems showcased on them found their way onto various Mercedes-Benz and Maybach versions. The Vision GLK FREESIDE and TOWNSIDE concepts that bowed in January 2008 gave important hints about the new GLK-Class compact SUV that was revealed in the spring of the same year.

The three Concept BlueZERO variants presented in 2009 at Detroit signalled the advent of the environmentally-friendly, alternative powering solutions at Mercedes-Benz. The fuel-cell and electric drive technologies were used to then develop the B-Class F-CELL, the smart fortwo ed and the A-Class E-CELL.

In 2009, Mercedes-Benz took the wraps off the Vision S 500 PLUG-IN HYBRID concept car, which used a V6 direct-injection petrol engine linked with an electric unit that, at need, can autonomously propell the vehicle for a range up to 30 km. One year after, the Concept Shooting Break served as an elegant design proposal that mixed the flowing, curvaceous lines of a 2-door model and roomy architecture of a wagon to create a new kind of coupe. The project has already been greenlighted for mass production and it will be officially revealed in 2012 in the form of the new CLS Shooting Break. Nevertheless, the second generation of the CLS-Class introduced at Paris in 2010 took its inspiration from the lines of the above-mentioned concept.

Last, but not least, the Concept A-Class premiered in April 2011 at the Shanghai Motor Show points towards a new generation of compact-sized Mercedes-Benz models. The third generation A-Class hatchback will be released during spring next year and will feature a consistent part of the technical advances previewed on the concept car.

Read more consistent details about the history of modern Mercedes-Benz concept vehicles >> HERE

Copyright © 2011, Mercedes-Benz-Blog. All rights reserved.