Thanks to re-engineered geometries and enhanced manufacturing processes, we have succeeded in keeping the weight of the new air-cooled EURO 6 charge air cooler constant, in spite of larger cooling surfaces and significantly improved component robustness and durability. Performance density was increased at the same time. The charge air coolers also reduce the installation depth of the cooling module by a further 14 mm, hence optimizing air flow throughout the system. As a result, the power requirement of the fan can be reduced without impairing cooling performance. Furthermore, new design measures must accommodate the increasingly higher thermal and pressure loads that charge air coolers are subjected to.
Indirect charge air cooling systems use extremely compact coolers that are cooled by the coolant of the separate low-temperature cooling circuit. Since the low-temperature radiator has a large front surface and is swept by the cold cooling air flow, very low charge air temperatures can be achieved. Due to their superior efficiency (as compared to a charge airair cooler), they can be designed with very compact dimensions and mounted onto the engine. In transient driving conditions, they provide for a much more stable intake air temperature and thus help reduce fuel consumption.