Testing of the New Maybach

Press Release

Method in the torture

• The practice: 2.5 million kilometres of testing in nine countries
• The prototypes: 27 hand-built prototypes put through two years of testing
• The procedure: from the icy cold of Sweden to the desert heat of Dubai and Arizona
• The programme: a 6,000-kilometre endurance test on the Nürburgring circuit
• The test rigs: new type-12 engine subjected to over 36,000 hours of extreme testing

Stuttgart - The Maybach is the end product of around three years of development work. In this time, the new high-end luxury saloon has covered 2.5 million kilometres and successfully met the extreme demands of a wide range of tests. In their quest to ensure the reliability of the new Maybach and the readiness of its innovative technology, Mercedes engineers took 27 hand-built prototypes, and 14 test vehicles and pre-production models on a journey over three continents and nine countries. "We test our new models under the most exacting conditions conceivable," confirms Maybach project manager Professor Hermann Gaus. "The Maybach had to undergo the same strict testing programme which new Mercedes models are subjected to before they can go into production. That means placing huge demands on the functionality, reliability and durability of the vehicles. Our aim was to develop a car which would function perfectly in all types of climate and on all kinds of road surfaces anywhere in the world." The following are just some of the elements included in the exhaustive testing programme for the new Maybach:

• 720 days of stresses and strain for a total of 41 test vehicles, prototypes and pre-production vehicles;
• a total of over 2.5 million kilometres of testing in Europe, America and Asia;
• hundreds of unforgiving tests on the test rig at the Mercedes Technology Centre in Sindelfingen, Germany, involving all bodywork and chassis components;
• 24 crash tests using complete vehicles, plus a large number of crash and structural tests on individual components. Test stations: from Arizona to Kiruna Pre-testing of the Maybach got underway in 1999. So-called "mules" concealed the technology of the new high-end luxury saloon under the body-work of a lengthened and widened W 140-series S-Class. They served as a rolling test laboratory for the engine, chassis, electronics, seats and other vehicle components. Whilst these mules were churning out kilometre after kilometre in testing, the first Maybach prototypes were taking shape at the Mercedes Technology Centre (MTC) in Sindelfingen. Hand-built and camouflaged to the point of disfigurement, they emerged at the beginning of December 2000 to make their first forays onto roads and test tracks in every type of climate the Earth had to offer:
  • Engines, tyres and cooling systems were given a thorough work-out on the high-speed oval track in Nardo, southern Italy.
  • A testing facility in Barcelona (Spain) was the location for testing of the chassis, air suspension system and steering.
  • At the DaimlerChrysler test track in Papenburg (Germany) the Maybach development experts put the mules, prototypes and pre-production vehicles through their paces during several weeks of in-depth testing.
  • On the unsurfaced roads of northern Norway, and the DaimlerChrysler testing grounds in Laredo, Texas, the bodywork and chassis came in for a pounding at the hands of gravel, potholes and stones.
  • On a frozen lake near Arjeplog in Sweden, Maybach engineers worked on fine-tuning the Electronic Stability Program (ESP®) and high-performance electrohydraulic braking system Sensotronic Brake Control (SBCâ„¢).
  • The two climate control systems on board the high-end luxury car successfully came through their toughest tests in everyday conditions in Kiruna (Sweden) and under the burning sun in the US desert state of Arizona.
  • On the Großglockner mountain pass (Austria) and at Stilfser Joch (Italy) the braking system of the luxury saloon had to withstand constant stresses and strain.
  • Dubai (UAE) played host to several weeks of city testing in stop-and-go traffic, with outside temperatures exceeding 40 degrees Celsius.
  • On Mont Ventoux (France) Maybach engineers ran checks on the cooling system of the twelve-cylinder engine.
  A test of endurance: non-stop testing in everyday traffic conditions For two pre-production vehicles May 2002 signalled the start of systematic non-stop testing in city traffic, and on country roads and motorways. This "mixed-road endurance test" is employed as standard in the development of all Mercedes models, and is therefore part of the compulsory programme for the Maybach as well. For the engineers it is a source of accurate data concerning the long-term durability of the vehicles and their components. The driving and route profile of the endurance test is precisely defined so that every kilometre is covered according to strict testing guidelines which can be reproduced. The testing programme consists of several pages. It instructs the drivers exactly how long the car has in order to prove itself in stop-go-traffic, on country roads, motorways and mountain roads, and what additional tests of durability it has to confront along the way. Fast forward: 300,000 kilometres in just a few months For years now, DaimlerChrysler engineers have set themselves extremely high standards when it comes to the durability of their vehicles. Each test the company runs to this end is intended to simulate the stresses on a vehicle over its entire service life – and when it comes to the premium models from the Stuttgart-based car maker, that is normally a very long time. The aim of the durability testing is to simulate within the space of a few months the strain normally only exerted on a customer's car after it has covered up to 300,000 kilometres in everyday service. In order to get through this imposing workload, many tests run in fast-forward mode. One example is the heathland endurance test. It takes only 2,000 kilometres on a specially designed torture track for the prototypes and pre-production models to reach a degree of wear and tear which a car will only normally experience towards the end of a long service life. The extreme tests regularly carried out on the Hockenheimring and Nürburgring racing circuits fulfil a similar function. The Maybach clocked up 6,000 kilometres on each track, to a tempo of fixed and precisely calculated lap times. And let us not forget the 15,000 kilometres the new model completed over the gravel and unsurfaced roads of Sweden, and the full-load testing for axles and transmission over 50,000 kilometres at the high-speed circuit at Nardo in southern Italy – both serving to simulate in double-quick time the stresses and strains exerted on a car in everyday service. Test rigs: axles and bodywork under extended periods of stress In addition to the testing on track and road, the Maybach engineers also cast a close eye over the prototypes on simulation test rigs. This state-of-the-art equipment allows them to channel forces and movements into the suspension through the wheels in order to reproduce typical driving maneuvers such as braking and cornering. All the factors which effect ride comfort and driving dynamics are then recorded, i.e. suspension performance, fluctuations in wheel load, body vibrations, body damping, kinematics and elastokinematics. Analysis of the test results enabled the engineers to work out further development steps and optimize the vehicle's technology. The Maybach engineers also used the driving dynamics simulation test rig to look into the vehicle's handling characteristics in typical steering and driving maneuvers. For example, the rig was able to reproduce the full range of wheel and body movements in a stationary circle test, thus allowing conclusions to be drawn - concerning the over/understeer characteristics of the car – based on practical results. Vibration analysis benefited from a similar level of reality-based testing. Data describing the surface profiles of various different country roads and motorways was fed into the computer in the power-assisted hydraulic vibrations test rig. Hydropulse pulsations under all four wheels of the test car reproduced the effect of the uneven roads. Up to 140 acceleration sensors fixed to the inside and outside of the car registered the wheel and body vibrations during the test. A further testing station was the flat-surface test rig, which was used to simulate a level road surface. The test engineers set speeds of over 150 km/h, analyzing steering angle, wheel alignment and camber, as well as tyre characteristics when taking corners at high speed. This is another example of how cutting-edge computer-based technology can allow tests car-ried out on the road to be reproduced, and the results confirmed, under laboratory conditions. Engine testing: 2.7 million test kilometres using 122 test cars The new type-12 engine in the Maybach has also successfully come through a demanding programme of testing on the road and the test rig. The Stuttgart-based engineers sent a total of 238 engines away for testing. Around half of these were put to work in test cars and demonstrated exceptional durability over a distance of some 2.7 million kilometres. The testing schedule for the engine – which boasts the highest output and torque rating of any series-produced passenger car power unit - involved an 800,000-kilometre endurance test on German motorways, trunk roads and country lanes, as well as a large number of tests conducted under extreme climatic conditions in locations as contrasting as the Earth's hottest point in Death Valley, and Kiruna, Sweden's most northerly town. Finally, the twelve-cylinder engine successfully underwent several weeks of tuning tests in the rarefied atmosphere of the 3,390-metre Pico de Veleta in the Andalusia region of Spain. The road in the Sierra Nevada mountains is one of the highest routes passable by car anywhere in Europe. The newly developed Maybach engine experienced the opposite extreme of its testing marathon on the testing rigs at Stuttgart-Untertürkheim. Months of operational tests to fine-tune the ignition, fuel injection and tur-bochargers were complemented by noise and vibration checks. This re-sulted in 116 test engines clocking up 36,745 hours on the test rig. Almost a third of this work schedule came under the heading of "cyclical endurance testing" and was based on a precisely stipulated sequence of exacting engine speed, load and temperature tests. Equally impressive as the high intensity of the testing are the vital statistics of the Maybach power unit. Its 5.5-litre displacement, twin turbochargers, 405 kW/550-hp output and maximum torque of 900 Newtonmetres secures its position as the world leader among passenger car engines in terms of output and torque rating. This engine power ensures the authority in any driving situation that you would expect from a Maybach. It is also the product of DaimlerChrysler's many years of experience and irrepressible expertise in the development, construction and manufacture of twelve-cylinder engines. The German car maker is the world's largest producer of V12 engines for passenger cars. The wind tunnel: detecting noises using special microphones The Maybach development engineers clocked up hundreds of hours in the wind tunnel with prototypes and pre-production models. This is where the focus shifted to aerodynamics and, above all, aeroacoustics – a key area of development which goes towards ensuring the low noise levels on board the new high-end luxury saloon. The engineers used state-of-the-art testing processes in the aeroacoustics tunnel to identify parts of the bodywork which may have been causing troublesome wind noise or vibrations and took action to rectify any irregularities. Potential problem areas included the sophisticated sealing systems on the joins of the body panels, which are an effective tool to prevent wind noise from developing in the gaps, even at high speeds. Furthermore, comprehensive insulation of the individual body panels prevents any wind noise from penetrating into the interior of the Maybach. This insulation consists of sealing all the way around the doors, plus additional weatherstrips on the front wings and roof pillars. The Maybach engineers paid particular attention to low-frequency interference, which can be caused by vibrations in larger components. Aeroacoustic data, for example, provided important information for the rigid, low-vibration construction of the cover panels for the underfloor section and its attachment points. Through the use of a wind deflector with four precisely calculated notches worked into its plastic profile, the Maybach experts have managed to cancel out the annoying booming which detracts from the ride comfort when the sliding sunroof is open. The notches generate tiny whirlwinds which allow them to suppress the annoying noise. Crash tests: the car body is placed under extreme pressure In the safety area of the Mercedes Technology Center the new high-end luxury saloon was subjected to a large number of successful crash tests, which it emerged from with flying colors. The programme included a frontal offset impact at 64 km/h and frontal collision with full overlap, plus the side-on impacts which are part of both the European and American NCAP (New Car As-sessment Programme) testing procedures. This testing programme focussed on areas including the safety features of the innovative new reclining seats in the rear of the Maybach 62. Their ground-breaking technology ensures unbeatable occupant protection in any seating position. Months before the first crash tests actually took place, sophisticated crash simulations and calculations relating to wear on materials provided the engineers with valuable knowledge regarding the optimisation of the body structure. During the development of the Maybach, the engineers played through several hundred crash simulations. This procedure has a number of advantages: for example, during the animation of the results the engineers can block out parts which are obstructing their view, plus they can use a computer to analyse even the smallest details in the deformation of individual vehicle components. To carry out their calculations, the engineers break the car down into a virtual grille structure, what is known as the finite element model. It consists of a large number of small elements such as triangles, rectangles, cuboids and thick lines, which are connected at the nodal points. The more precisely the deformation of the structure is to be assessed, the tighter the meshing of the grille. The body of the Maybach, for example, was broken down into around 300,000 finite elements and more or less the same number of nodal points. A crash test, which in reality takes a tenth of a second, is analyzed by the computer in approximately 150,000 time intervals. For each of these fractions of time, the computer calculates the responses of the different elements as they crumple under the pressure of the impact. Virtual reality: important preparatory work for testing in practice A range of other components in the high-end luxury saloon also proved their mettle on the computer screen long before the first tests took place in practice. With a helping hand from virtual reality technology (VR), Daimler-Chrysler engineers conducted simulations of a car in everyday service. This allowed them to gain important information about the Maybach as far back as the early conceptual phases of the project, data which they then repeatedly checked and fine-tuned in subsequent real-life testing. "FADYS" (simulation of driving dynamics) is one of the leading programs of its type. In use at DaimlerChrysler for several years and under constant development, it has been a prominent aid in the development of a host of new models – in particular in the adaptation of the Electronic Stability Program ESP® and other state-of-the-art driving safety systems. FADYS simulations are so close to reality that the computer can start delivering important data on vehicle handling and the operation of the control systems as early as the concept phase of a new model. At the same time, the Maybach engineers had no intention of relying solely on their findings from the virtual world, and their calculations also took into account - where possible - data compiled from real-life testing. This in-cluded information on body movement, axle kinematics, wheel slip, wheel forces, tyres and engine torque which had been compiled in road and rig tests using test vehicles and prototypes, and stored on computer. The technical components of the Maybach were also actively integrated into the calculations. Control units, electrohydraulic brakes and other systems were linked up to the simulation computer via a data line, and carried out its commands. This allowed the engineers to form a bridge between simulation and reality. "Hardware-in-the-Loop" is the technical term the automotive engineers use for this method. In tandem with the high-capacity FADYS program it can create driving dynamics simulations in real-time -- the engineers can observe the handling characteristics of a car on a computer screen and call up the relevant values at any time. This was how they analysed the functioning of the electronic control systems, for example, in various different driving situations. Simulations also allowed the experts to determine the settings for the ESP®, ABS and Twin-SBC™ control units in advance, before optimising them in real-life driving tests.