Long-term rise of oil prices, increasingly stringent emission regulations, combined with emerging regulations to reduce truck engine idling present a unique opportunity for hybrid trucks. Tutto Industria de Sistemas de Tracao Electrica is a Brazilian Company located in Caxias do Sul which is dedicated to develop and commercialize electric and hybrid drive trains for commercial vehicles. In this paper a case study for a Brazilian delivery truck application will be presented. First the fundamental architecture of a series hybrid delivery truck is described and simulation models for a conventional 8 t delivery truck and the responsive hybrid electric truck are built, and serve as a basis for powertrain components and control strategy analysis. Comparisons of the hybrid truck with the conventional truck are performed, and important factors relating to the vehicle performance (gross vehicle weight, drive cycles, control strategies) are investigated. In order to achieve realistic values, two representative drive cycles for beer and parcel delivery services in Brazil are used for cost/benefit analyses. Simulation results show that the hybrid truck with appropriately designed components can achieve comparable performance as the conventional truck, but much better fuel efficiency and lower emissions. The amount of saved fuel is highly correlated with the type of drive cycle and especially the amount of vehicle stops where the engine can be shut off. Besides the fuel saving, the cost benefit of reduced maintenance due to lowered brake wear, extended maintenance intervals due to reduced engine load/operation time are discussed as well.