The increasing world population depends strongly on the energy-intensive agricultural productivity. The majority of this energy is obtained from fossil fuels which will deplete in the foreseeable future, and subsequently its price will increase even further than we are seeing today. Tractors with diesel fuelled combustion engines play a vital role in the mechanical agricultural production process for foods, bio-fuels and raw materials. Hence, the motivation to boost a tractor's overall efficiency to reduce future operating costs, i.e. overall fuel consumption, and also keeping emissions of environmental impact to a minimum. Pursuing these goals is a cluster research project called, "Einsatz von Lithium-Ionen-Batterien in Off-Road Nutzfahrzeugen zur Effektivitäts- und Autarkiesteigerung (LIBOFF- Road)"1, with the following partners, John Deere Werke Mannheim, enders Ingenieure GmbH, Zentrum für Sonnenenergie- und Wasserstoff-Forschung, Fachhochschule Köln Institut für Landmaschinentechnik und Regenerative Energien and Technische Universität München Lehrstuhl für Verbrennungskraftmaschinen (LVK). The research work is subsidised by the BMWi and is part of an innovative alliance in an established development plan called, "Lithium Ionen Batterie LIB 2015", supporting further research in the field of lithium ion energy storage. The Institute of Combustion Engines' (LVK) main research goal is to develop hybrid strategies and a complete vehicle simulation model for a hybrid tractor to analyse the potential reduction in fuel economy and emissions. Engine test bed measurements will provide data for calibrating and validating specific models. This paper will give a partial insight into the developed models and energy management strategies that are implemented in the complete parallel hybrid electric vehicle (P-HEV). It will begin with a brief insight into the specific cycles used for simulation and test bed purposes and will finish with a discussion of the simulation results compared with real test bed measurement data.