MAN D1556 engine

Groundbreaking in the 9-litre class: The MAN D1556 diesel engine for off-road applications. This straight-six power unit delivers between 205 and 324 kW (275 and 434 HP). Its highest power variant achieves a maximum torque of 1,970 Nm at speeds between 1,150 rpm and 1,300 rpm. Even at low speeds, the MAN D1556 delivers high torque. And with a dry weight of just 860 kg, it is the lightest off-road engine in its displacement class. “With the D1556, the MAN Engines engineers have succeeded in developing an engine with high power density and compactness that is perfectly suited to the requirements of off-road applications. In addition, as the first 9-litre engine developed by MAN Engines, it completes our engine portfolio for construction and agricultural machinery and bridges the gap in performance between the well-established MAN D0836 series with 6.9-litre displacement and the D2676 with 12.4-litre displacement,” explains Hubert Gossner, head of off-road sales at MAN Engines.

Compact and powerful

The broad power and torque plateau of the D1556 is attributable to the turbocharger with its variable turbine geometry (VTG), as well as the common-rail system which ensures injection pressures of up to 2,500 bar. Based on these technologies, the power unit with its bore of 115 mm and stroke of 145 mm develops its power uniformly and dynamically, even at the lower end of its speed range. The high compression ratio also results in more efficient fuel combustion, which together with the modern engine design leads to incredibly low fuel consumption levels across the entire map range. Further advantages of the VTG turbocharger lie in the wide range of deployment profiles and in its compact design which make it an ideal fit within the overall D1556 concept. Its overall dimensions of 1,414 x 807 x 1,103 mm (length x width x height) mean the 6-cylinder engine has one of the lowest installation volumes on the market. This offers an ideal opportunity for designers to perfectly integrate the engine into construction machines such as excavators, wheel loaders and mobile cranes or into agricultural machines such as tractors, forage or combine harvesters.

Ensuring compliance with current emission standards

Thanks to the equally space-saving MAN Engines modular exhaust gas aftertreatment (AGN) system, the engine meets current emission standards such as EU Stage V and US Tier 4. Two DOC/DPF modules (diesel oxidation catalytic converter / diesel particulate filter), as well as an SCR (selective catalytic reduction) system with a special mixer are used for this purpose. The AGN offers great flexibility, since its individual components can be installed in a wide variety of positions. For an emissions downgrade to Stage IIIA/IIIB level, use of the SCR system is sufficient. In general, exhaust gas recirculation is not necessary for the D1556, creating additional savings in terms of space, weight and cost. This further reduces the complexity of the system.

Ultra-reliable

The MAN D1556’s high level of reliability is supported by features such as these, along with MAN Engines’ many years of practical experience in the off-road field with various different installation situations and load profiles, as well as the use of established, thoroughly tried-and-tested technologies and materials sourced from the mass production of MAN commercial vehicle engines. OEM customers can also benefit from MAN’s worldwide service network, as well as the option to customise engine characteristics in line with their own working needs. This completely newly developed diesel engine celebrated its premiere at the Agritechnica trade fair in Hanover in 2017. In addition to applications in agricultural machinery, the 6-cylinder engine is already being used successfully in proprietary MAN buses and trucks.