Like every daring project, it all began with a blank sheet of papers. After a long period of in-house development, the new Actros eventually had to taste tarmac for the first time. Prototypes "dressed" in deep black "clothes" started rolling out of the Mercedes-Benz truck R&D centres onto the streets of the world. Around 20 million miles were covered during the testing phase, going from the hot South Africa up to the freezing-cold Arctic Circle, to demonstrate the new Actros is ready to successfully handle extreme weather conditions. The truck also showed an outstanding reliability, suffering no overhaul in 1.2 million kilometres of intensive run. Last, but not least, the engine has undergone over 60 million kilometres of thorough testing.


No other truck has been as thoroughly developed and tested before its production launch as the new Mercedes-Benz Actros. The foundations for development were laid as many as ten years ago, while the components and the complete vehicle have undergone five years of testing. During this time, the new Actros has clocked up around 20 million miles on the road, including in intensive customer driving tests. Then there were the extremely rigorous tests on test rigs, torture-track testing and other extreme examinations.

It all began on a blank sheet of paper

The story of the new Actros really did begin on a blank sheet of paper. To come up with a successor to the successful outgoing model, designers, developers, marketing specialists, product managers and everyone else involved started from scratch. Rather than make the new Actros a further development of its popular, tried-and-trusted predecessor, the aim was to start afresh so as to come up with a perfect and future-proof solution for operators and drivers. No stone was therefore left unturned during development.

The cab comfort features were redefined and redesigned, and the cabs themselves were dimensioned accordingly.

This approach gave rise to an all-new range structure: instead of two model series with their own characteristics for long-distance transport, short-distance transport and construction work, there are now three model series, each one specialising in one of the above disciplines. The first member of the new, three-strong family of Mercedes-Benz heavy-duty trucks is the new Actros, which exclusively covers the long-distance-transport segment in all its guises. The other members of this family will follow.

New range structure with the focus on long-distance transport

Focussing on the new Actros as a premium truck for long-distance transport opened up many new possibilities. For the first time, both the inside and outside of the cab were designed specifically for a single field of application. Development was based on several 1:4 scale models, which allowed the designers great freedom in determining the direction the new Actros would take.

From these, six 1:1 scale models were derived – three for the exterior and three for the interior. Even the very first interior sketch defined the clear visual distinction between the working and living areas – a first in truck development.

Some 1600 Daimler Trucks staff worked on the new Actros, including vehicle developers, testers and the major-component developers concerned. Their work was frequently monitored by the testing department as well as in special Truck Clinics. In four of these Clinics, a total of 638 operators and drivers were interviewed at great length.

Long before production started, the new Actros experienced the Arctic Circle in winter and the searing heat of Spain's Sierra Nevada in summer. It negotiated all kinds of roads in Turkey and got a taste of desert sand in South Africa.

Engine has undergone over 60 million kilometres of intensive testing

The launch of the new Actros also marks the introduction of a new generation of six-cylinder in-line engines. The outstanding quality of the new engine generation was evident even during its development. Extreme reliability and durability were among the most important development objectives. In order to achieve this, the engines were tested under the toughest of conditions, all over the world. To date, the engines have clocked up in excess of 60 million kilometres in endurance testing on test rigs and in real-life operation, for all emissions classes. No engine ever before has been as intensively tested.

Tested under the toughest of conditions, from the Arctic Circle to South Africa

The real-life road tests also covered all climatic conditions as well as extreme road conditions and gradients, ranging from an Arctic winter to an extremely hot desert climate. Real-life testing also included customer driving tests in the previous Mercedes-Benz Actros.

Outstanding reliability: 1.2 million kilometres without overhaul

On top of all this came customer driving tests of a very special nature, from
Mercedes-Benz's point of view: in North America and Japan, more than 70,000 engines are now working successfully in Freightliner and Fuso heavy-duty trucks. New-generation engines – albeit in a special configuration for the respective region – have already been in daily customer use there since 2007 (North America) and 2010 (Japan).

The findings from the tests conducted under extreme conditions have proved very positive. For instance, the new engine series achieves a "B-10" figure of 1.2 million kilometres, i.e. 20 percent higher than previously, in European long-distance transport. This means that the engines can cover at least this distance without the need for a major overhaul.

OFFICIAL PRESS RELEASE

Stuttgart/Mannheim, Germany, May 20, 2011

Teams from all departments – from Development to Production to Sales & Marketing to After Sales – worked in close collaboration with one another during the development of the new Citaro. Their joint objective was to achieve supreme quality, in order to best prepare the new Citaro for the rigours of urban and rural regular-service operation


State-of-the-art design and development methods

The top quality achieved in the series production of the new Citaro is rooted in state-of-the-art development methods, such as HiL (Hardware in the Loop) and CAE (Computer-Aided Engineering). Examples for this type of quality assurance include component strength analyses, evaluation of vehicle vibrations and crash test simulations – all this and more is carried out by computer.
All safety-relevant components were analysed using the FMEA method in the early phases of development. The failure mode and effects analysis seeks to anticipate potential problems and prevent them. To put it in simple terms: the developers check everything that might go wrong in advance and undertake appropriate measures, thereby eliminating faults before they even occur. The development findings were backed up by numerous computer-aided calculations for components and assemblies as well as for the vehicle as a whole.

A laboratory bus examines production

The troubleshooting carried out during development of the new Citaro was not a purely theoretical affair, however: all the main body segments were scrutinised in rough form during the development phase when the prototype was built. It was therefore possible to examine potential cable chafing points, component accessibility or other critical issues directly on the vehicle, right from the outset.

The very first prototype of the new Citaro was already assembled on the production line so that any problems in the manufacturing process could be remedied immediately. Besides this, a special “laboratory bus” passed through each production station several times. Using this procedure, Mercedes-Benz was able to train the production workers and, at the same time, identify critical processes. Exact prototype protocols were kept to log all change requests for the bodyshop, assembly and testing, for instance. Workshops were held at regular intervals to resolve any flaws and document the progress in detail.

Testing under the toughest conditions on test rigs and the road

Individual components and assemblies, as well as complete buses were put to the test under the toughest conditions. The new doors, for example, were subject to endurance testing on test rigs, when they had to complete one million load cycles - the equivalent of a bus's entire service life – without any damage. Tests with seven carefully camouflaged prototypes were then conducted at the proving ground as well as on the road. Rigorous testing was also carried out in extreme climatic conditions, meaning that the new Citaro has already faced both the bitter cold of the Scandinavian winter and the searing summer heat in Spain and Turkey. The new urban bus furthermore had to prove its mettle in rough-road and endurance testing, which included a circuit of specially selected poor roads in remote regions of Turkey.

Successfully completed crash tests and pendulum impact tests in accordance with the ECE R29 standard for coaches, as well as rollover calculations based on the future ECE R66/01 standard, are testimony to the design’s high standard of safety.

The extensive programme of testing concludes this spring when new Mercedes-Benz Citaro buses will commence customer trials in everyday regular-service operation before series production gets underway.

The new Citaro: launching with rigid and articulated buses

Mercedes-Benz will be phasing in the high-volume model versions of the new Citaro over the course of 2011. The focus will be on urban and rural variants with a length of 12 metres and 2 or 3 doors, as well as the urban and rural versions of the articulated Citaro bus with 3 or 4 doors. The buses are driven by horizontal or vertical diesel engines from the OM 906 and OM 457 series in the familiar versions and power ratings. Further variants of the new Citaro will follow in 2012. The new Mercedes-Benz Citaro has been future-proofed, with all installation spaces already prepared for the future Euro VI emissions standard. The corresponding drive units will be launched at a later time. This progressive switch to the new model generation guarantees thorough testing of all versions, high quality, plus a continuous supply of vehicles without any disruption to customer deliveries. The complete range of new Mercedes-Benz Citaro models, including all rigid and articulated variants, the low-entry Citaro LE as well as the CapaCity, is due to become available over the course of 2012/2013.