Vehicle electrification technology has demonstrated its effectiveness for passenger vehicles, mainly due to environmental performance needs to meet fuel economy and green-housegas emissions standards. Military vehicles require, among other specific features, not only the ability to move undetected but to perform at the lowest combined fuel and energy consumption possible. An experimental prototype HMMWV XM1124 with a series hybrid powertrain, which provides the ability for electric mode only and hybrid operation for reducing fuel consumption, is being investigated. The aim of this paper is to create a model of XM1124, validate it and utilize it to analyze the effect of vehicle electric range and performance. Additionally, the validated model allows evaluation of various operating strategies and hardware configurations for reducing the fuel consumption and improving vehicle performance.