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The rapidly growing amount of software in cars reshapes the automotive industry. The software has a significant influence on the production lines, due to the time required to flash it onto the vehicle and its capabilities to test vehicle functions during production. In this paper we identify the main pain points regarding software in the manufacturing process by performing a structured analysis on the experiences made at a major car manufacturer over last two years. Consequently, the paper analyses the possible approaches to address the challenges.

The automotive industry changes rapidly. New players, concepts, and technologies from the Information Technology (IT) domain enter the market and software receives a high priority. Inside the vehicle, the number of components, which consist mostly of software, are increasing and more and more software-based functions are offered. In addition, High Performance Computers (HPCs) are continuing to be integrated into vehicles. These aspects lead to several challenges with current vehicle diagnostics, but also enable new opportunities in that field. However, in the specific area of vehicle diagnostics, there exists only very limited literature that considers current challenges and new possibilities for future vehicle diagnostics. Some literature deals with the general automotive system design or shows results from about five years ago. The viewpoints of an Original Equipment Manufacturer (OEM) are not included there.

The objective was to develop a modem engine to succeed the M 102; 2.6 million of these units were made between 1979 and today making it the most successful Mercedes-Benz four-cylinder petrol engine to date. The new M 111 coordinated production set-up together with the familiar M 104 six-cylinder four-valve engines and the 600 diesel series. Emphasis has been deliberately given to improved torque rather than very high volumetric efficiency. This has made it possible to apply four-valve technology, which was originally only to be found in motor racing, in such a way that ordinary customers can benefit form advantages such as high torque and raised power output, as well as reduced fuel consumption and emissions. Extensive noise-reducing measures in the engine ensure that, despite the higher power output and lower engine weight, noise levels have also been improved.

The California Air Resources Board (CARB) has proposed procedures for the analysis of non-methane organic gases (NMOG) to determine the ozone forming potential (OFP) of automotive exhaust. For realization of these methods two differently configured GC systems are necessary. In order to reduce the efforts concerning costs, maintenance and quality control of two analytical instruments, a single run method is developed for routine analysis. This method allows identification and quantification of individual hydrocarbons (IHC) in the range of carbon numbers C2 to C12. Analytical problems arising from high contents of water and carbon dioxide in exhaust samples are discussed. Water reduction is obtained by a Nafion® Dryer by means of membrane diffusion of polar compounds. Contamination as well as memory effects due to this sample work up are described. Sample pre-concentration of 50-200 mL diluted automotive exhaust is performed using a triple phase “mixed bed” adsorption tube at O°C.

The settings of adaptive suspension elements may be switched from a comfortable “soft” characteristic to a safe and “firm” characteristic. Thus the possibility is given to not only improve the ride comfort, but the dynamic driving behavior as well, since no compromise must be made between these two criteria when tuning the suspensions. Such systems seem to be very promising for commercial vehicles, as - because of their changing loading conditions - it is very difficult to design an optimal suspension system using conventional springs and dampers. This paper describes the influence of shock absorbers and air springs with variable characteristics on the ride comfort and the dynamic behavior of a 15-t-truck by investigations done with a simulation system. A series production vehicle without adaptive suspension elements serves as basis. At first the results of measurements and simulations are compared and show a very good concurrence.

Sunroof buffeting is examined experimentally and numerically in this paper. Despite the fact that some consider the simulation process for sunroof buffeting to be mature, there remain substantial uncertainties even in recently published methodologies. Capturing the frequencies and especially the sound pressure levels correctly is essential if CFD simulations are intended to be used during early stages of a car development process. Numerous experimental results of sunroof buffeting and the interior low-frequency characteristics of a 2013 Mercedes-Benz S-Class have been used to develop a simplified car model: a full-size S-Class model with slightly simplified geometries in the interior as well as at the exterior. To avoid the effects of numerous different materials in the interior, it is solely made from polyurethane and aluminum and built to maximize its structural rigidity and air-tightness.

In this paper, the differences between a production car of the 2018 A-class and an early stage vehicle model with a mostly similar outer skin are examined experimentally and numerically. The aerodynamic development of vehicles at Mercedes-Benz is divided into several phases. When comparing force coefficients differences can be observed between these distinct hardware stages as well as when comparing steady state simulations to wind tunnel measurements. In early phases when prototype vehicles are not yet available, so-called aero foam models are used. These are well-defined full-sized vehicle models, as the outer skin is milled from Polyurethane. Important aerodynamic characteristics such as a motor compartment with a cooling module, deflecting axles with rotatable wheels and underbody covers are represented.

Over the last 40 years it has been possible to lengthen recommended passenger car engine oil drain intervals by up to five times, despite the substantial increases in oil stress through continously rising demands on performance and environmental acceptability. Behind this considerable progress lie improvements in engine design and production technology and the development of suitable advanced engine oil formulations. With increasing oil drain intervals comes a growing uncertainty as to exactly when the oil change should best be made: a fixed mileage applicable to all vehicles is preferred for its practicality but the optimum depends on the driving history of individual vehicles. In Europe a 15000 km oil drain interval is now normal. A further extension based on a fixed interval would give an advantage to a minority of customers but could seriously compromise the durability of engines in the overall vehicle population.

Car manufacturers spend steadily increasing efforts to design cars in such a way that material selection, production steps, use and recycling, respectively disposal, fulfill environmental expectations and requirements to an optimal, best known extent. The additional application of Life Cycle Assessment (LCA) for car design supports a better and virtually “objective” understanding about resource consumption and environmental impacts during the complete life cycle of cars. Thus, LCA opens a high potential to contribute for future cars to improve them in terms of ecology as well as with regard to technological and even economic aspects. Holistic Life Cycle Costing (LCC) can hereby serve in a useful complementary manner. Co-operating with experienced partners and taking part in the development of LCA standards, Mercedes-Benz is developing LCA as a supporting tool for vehicle design.

Meta material has been known for many years and the physics are well known since decades. But the challenge has always been to put the know how into (mass) production. This was the reason why no meta material has found its way into the automotive industry so far. But now things have changed: meta material became Meta Design and is going into serial production in 2024. Meta Design is a tunable spring mass system with foam acting as the spring and heavy layer as the mass. Meta Design is characterized by cavities in the foam and concentrated masses of the heavy layer as functionalized mass pins. By tuning the size of the cavities and the weight of the mass pins the acoustic performance can be adjusted to the requirements of each individual car line. After preliminary simulations, flat samples were tested in the lab. The next step was launched: the production and testing of a handmade prototype part of a firewall insulation for a Mercedes-Benz A-Class.

The real-time concentrations of benzene, toluene, xylene, trimethyl-benzene and naphthalene in vehicle exhaust have been monitored during the FTP-cycle with a time-resolution of 20 ms and a sensitivity of 50 ppb. Using a laser mass spectrometer, the aromatic hydrocarbons in unconditioned exhaust gas at sampling positions behind the exhaust valve, before and behind the catalytic converter have been analyzed. The comparison of the emissions sampled before and behind the catalytic converter reveals the effect of dealkylation of the aromatic hydrocarbons in the catalytic converter. Whereas most of the aromatic hydrocarbons are burned in the hot catalytic converter, however, bursts of aromatic hydrocarbons are released at transient motor operation. In these moments, which can be attributed to phases of closed throttle valve and very low engine load at gear changes, a significant part of the C1-, C2- and C3- benzenes has been converted into benzene.

Secondary air injection after cold start gives two effects for reduced exhaust emissions: An exothermic reaction at the hot exhaust valves occurs, which increases the temperature of the exhaust gas. It gives sufficient air to the catalyst during the cold start fuel enrichment that is necessary to prevent driveability problems. Handicaps for the wide use of air injection include space constraints, weight and price. An electrical air blower was choosen to best satisfy all these requirements. The development steps are described. The result is a three stage radialblower with extremly high revolutions of about 18000 rpm. The system configuration and the outcome are demonstrated on the new C-Class of Mercedes-Benz. The results show emission reductions higher than 50 %, while also satisfying the development goals of noise, volume, weight and cost requirements.

After the introduction of four-valve technology for gasoline powered passenger cars, Mercedes-Benz consistently developed this technology also for Diesel engines. Based on the proven success of the prechamber combustion system, this new Diesel engine generation, which includes 4, 5 and 6-cylinder naturally-aspirated engines, will be the first four-valve Diesel engines to be installed in passenger cars. The naturally aspirated 3.0 liter 6-cylinder in-line engine which represents the high end of this generation will be offered for sale in all 50 states of the USA in the Executive Class models starting on January 1, 1994. Four-valve technology allows the prechamber to be located centrally between the intake and exhaust valves which results in a major improvement of the combustion process. In addition, this 6-cylinder engine has a resonance intake system controlled by two butterfly valves to maximize the volumetric efficiency of the engine.

Computational models directly derived from data gained increased interest in recent years. Data-driven approaches have brought breakthroughs in different research areas such as image-, video- and audio-processing. Often denoted as Machine Learning (ML), today these approaches are not widely applied in the field of vehicle Noise, Vibration and Harshness (NVH). Works combining ML and NVH mainly discuss the topic with respect to psychoacoustics, traffic noise, structural health monitoring and as improvement to existing numerical simulation methods. Vehicle interior noise is a major quality criterion for today’s automotive customers. To estimate noise levels early in the development process, deterministic system descriptions are created by utilizing time-consuming measurement techniques. This paper examines whether pattern-recognizing algorithms are suitable to conduct the prediction process for a steering system.

The valve timing of internal-combustion engines usually represents a compromise with regard to the requirements placed on power output and torque. This paper describes the development of a system for variable valve timing, taking the new Mercedes-Benz 4-valve engines as an example. Gas exchange calculation and tests carried out on a modified 4-cylinder engine have demonstrated that with two intake valve times and one specified exhaust valve time virtually the best possible torque characteristics combined with high power output can be achieved. Intake valve timing is adjusted dependent on load and engine speed by turning the intake chamshaft using a hydraulic-mechanically acting camshaft adjuster, whose functional principles are described in detail.