ABSTRACT Hino Motors, Ltd. (Hino) launched the world's first hybrid city bus in 1991. Since then, the same hybrid technology has been refined and applied to a range of commercial vehicles, from city and tour buses to light and medium duty trucks, expanding the commercial hybrid vehicle line up. After 20 years of refining this technology, in 2011 Hino launched an all new light duty hybrid truck in Japan. An alternate version of the truck was developed to meet the particular needs of the North American market, differing from the Japanese model in several important features. The Japanese model's automated manual transmission was replaced with a fully automatic transmission, and the motor and inverter specifications were altered. This paper outlines the development process and introduces various characteristics of the technologies employed in the North American hybrid model. Its focus is primarily on the performance evaluation process and results, including initial market survey, internal on-road testing, chassis dynamometer testing and in-use demonstration. 1. INTRODUCTION In recent years, the effects of air pollution and global warming have become an increasingly important issue worldwide. Since vehicle emissions are one key factor contributing to these environmental changes, countries around the world are implementing increasingly strict vehicle emissions and fuel economy regulations. With the increasing need for cleaner exhaust and CO 2 emissions in the commercial vehicle market, Hino Motors, Ltd. began focusing its environmentally friendly technologies research and development on hybrid systems in 1981. In 1991, this technology was utilized for the world's first heavy duty diesel electric transit bus, followed by mass productionof the world's first light duty hybrid trucks in 2003. Aiming for even more dramatic fuel economy improvement and lower hybrid system costs, the hybrid system and its components were redesigned and a new model automated manual transmission (AMT) light duty hybrid truck was developed, launched in Japan in 2011, to be followed by release overseas. To accommodate North American market needs, a torque converter automatic transmission (AT) Class 4 and Class 5 light duty cabover version of this new hybrid system was also developed. This paper explains the development process, hybrid system, performance evaluation and hybrid system benefits of this new model. The North American hybrid vehicle is shown in Figure 1.1, and hybrid system in Figure 1.2. Figure 1.1. Newly Developed Hybrid Vehicle Development of New Light Duty Hybrid Truck2012-01-1985 Published 09/24/2012 Toshihide Miyajima, Kunitoshi Shimizu, Koichi Yamaguchi, Shigeru Suzuki and Casey Cooper-Fenske Hino Motors, Ltd. Copyright © 2012 SAE International doi:10.4271/2012-01-1985Downloaded from SAE International by University of British Columbia, Monday, July 30, 2018Figure 1.2. Newly Developed Hybrid System 2. VEHICLE DEVELOPMENT Based on an independently developed hybrid system technology cultivated through many years, the new system was designed to achieve both emissions reduction and fuel economy improvement in a light duty hybrid vehicle tailored to meet the specific needs of the North American market. To that end, various development targets were set, including performance and cost, and plans to meet those goals were developed as outlined in section 2.1. 2.1. Development Goals 1. Fuel Economy Improvement: 30% over baseline diesel 2. Cost Reduction: 50% reduction compared to current model hybrid system cost 3. Regulation Compliance: EPA 2010 2.2. Development Approach To design a light duty hybrid truck well suited to North American customer needs, various system and component changes were needed to bring about revolutionary fuel economy improvement while still providing satisfactory power performance. One key change was the layout. In the previous system, the motor was directly coupled with the engine; in the new system, however, a clutch