Challenges in the development of high performance engines for the off-highway sector

To fulfil actual customer demands, R&D departments have to solve a trade-off between increasing power and torque demands in agriculture engine applications and to install the whole engine in the existing small engine package environment. Based on the increasing size of agricultural holdings, combined with the demand to reduce operating costs as much as possible, this has led to a requirement for tractors with high power and high torque, but which remain compact, highly versatile and highly manoeuvrable. To achieve good tractor manoeuvrability, a very compact package is required. In particular the width of the engine which is limited by the steering lock. The main focus subsequently is on operating costs. Both require a high power density. In addition to these demands, there is a high service life expectation of at least 10,000 hours. As well as a need for high power density, the tractor must be capable of operating continuously under a wide range of conditions. In order to meet these demands, dual-stage turbo charging technology with intermediate charge air cooling has been chosen. The following article will describe the segment-specific demands and the engine technology, including the special challenges for the agricultural application. Later on the validation process for such a special application product will be described.