This analysis is a comprehensive assessment of the fuel-saving technologies and technology packages for three representative diesel HDV types in India: a 40-tonne Gross Vehicle Weight (GVW) tractor-trailer, 25-tonne rigid truck, and a 16-tonne transit bus. These representative vehicle types are modeled after top-selling models in the Indian market based on sales data from fiscal year 2013-14. To model these vehicle types are accurately as possible, the study team acquired detailed engine maps that match the engine models in the respective vehicles and sought input on other vehicle systems from some of the leading Indian HDV manufacturers and suppliers.Using Autonomie as the vehicle simulation platform, the authors investigate the fuel consumption impacts of both individual technologies and combinations of technologies in the following areas: engine, transmission, driveline, aerodynamics, tires, material substitution (i.e., curb weight reduction), and hybridization. A baseline technology profile was created for each of the three vehicles based on the current technology levels of new vehicles in the market today. Then, the authors surveyed all of the efficiency technologies that could be applied to HDVs in India over the next 10-15 years and developed seven additional technology profiles for each of the three vehicle types. The results compare the fuel consumption performance of each technology profile against the baseline, and a sensitivity analysis is performed to analyze the impacts of altering critical parameters such as payload and drive cycle.