SAE International Start/Stop Test Drive Cycle Design and Implementation in Challenging Markets: A Mexico City Case Study 2017-01-1295

Political and social trends in the automotive industry production and consumption have changed in the last decade, driving a demand for more efficient, low-fuel consuming, clean vehicles in most markets nowadays. Recently the demand for such vehicles has been increasing and emerging markets are no exception; automakers all around the world have invested heavily in developing new electrification technologies that would comply with the newer and stricter regulations and environmental policies, being Start-Stop systems one of the preferred approaches due to their lower complexity and cost compared to full and mild hybrids. Mexico stands out as a challenge for the implementation of this technology due to its wide range of altitudes, temperatures, traffic jams, and some other contributing factors that can hinder this type of application - especially in its bigger and more populated cities. Specifically, Mexico City and its Metropolitan Area - where more than three million people travel from the suburbs into the city, suffering up to six hours of travel each day - account for more than 50% of hybrid and electric vehicles sold in the entire country. This paper proposes a specific drive cycle for vehicles with a Start/Stop system, based on data collected from different vehicle classes driven under different conditions in Mexico City, with the objective of assessing the correct scope, design, and implementation of Start/Stop strategies in similar markets. The conditions under consideration could impose a challenge in the different subsystems that interact during an automatic shutdown and restart of an engine, such as climate control, injectors, battery, and transmission.