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Modern trucks have to meet tough regulations for environment protection, which concern considerable reductions of fuel consumption, exhaust gas emissions and noise emission. As the fuel consumption rate of motor vehicle is directly influenced by its weight, reduction of the latter has high priority in the construction of vehicles. The use of compact, lightweight, high performance heat exchangers in engine cooling systems supports weight saving. High efficient charge air cooling improves not only the engine power, but also the fuel consumption, the exhaust gas emission and the life time of the engine. In addition a new developed jet ring fan ensures a stable air flow through the complete cooling system; combined with the Visco® clutch very low noise levels can be achieved. All these products are already manufactured in environment-friendly processes with easy recyclable materials.

Aluminum has a number of features which make it superior to the other non-ferrous metals (copper and brass) normally used for radiators in the past. Apart from the low specific weight, there are additional advantages, such as outstanding heat conductivity, strength, corrosion resistance and convenient forming and processing qualities. Brazed aluminum radiators with flat tubes and louvered serpentine fins are used for high horsepower engines and/or in confined spaces, while mechanically assembled round tube or oval tube radiators are preferred for smaller engines and/or where there is sufficient space. The excellent field results with car radiators have led to the use of aluminum radiators in trucks as well. More than 10 million fluxless brazed flat tube radiators with serpentine fins have been manufactured by Behr since 1975. Serial production for trucks was started in 1988.

When considering charge-air cooling in vehicle engines, it is necessary to distinguish between commercial and passenger applications on the one hand, and Diesel and gasoline engines on the other. The requirements for the various types of application will be outlined, and the characteristics of the various charge-air cooling systems discussed. In general, heat transfer rate and pressure drop are considered in evaluating the suitability of a charge-air cooler for a particular purpose. The effectiveness of such a procedure, however, tends to be limited. In order to create new criteria for evaluation, new terms such as the efficiency of density recovery and “half-value performance” have been developed. Optimisation of the core geometry according to the requirements and desired objective functions is necessary and shows that one single system cannot meet the wide range of requirements. Some practical applications and future trends are outlined.