400 Commonwealth Drive, Warrendale, PA 15096-0001 U.S.A. Tel: (724) 776-4841 Fax: (724) 776-5760 Web: www.sae.org SAE TECHNICAL PAPER SERIES 2006-01-1338 Hybrid System Development for a High-Performance Rear Drive Vehicle Kensuke Kamichi, Kazuomi Okasaka, Mamoru Tomatsuri, Takuji Matsubara, Yasuhiro Kaya and Hiroki Asada Toyota Motor Corp. Reprinted From: Advanced Hybrid Vehicle Powertrains 2006 (SP-2008) 2006 SAE World Congress Detroit, Michigan April 3-6, 2006 The Engineering Meetings Board has approved this paper for publication. It has successfully completed SAE's peer review process under th e supervision of the session organi zer. This process requires a minimum of three (3) reviews by industry experts. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE. For permission and licensing requests contact:SAE Permissions 400 Commonwealth DriveWarrendale, PA 15096-0001-USAEmail: [email protected]: 724-772-4028 Fax: 724-776-3036 For multiple print copies contact: SAE Customer Service Tel: 877-606-7323 (inside USA and Canada)Tel: 724-776-4970 (outside USA)Fax: 724-776-0790Email: [email protected] ISSN 0148-7191 Copyright © 2006 SAE International Positions and opinions advanced in this paper are those of the author(s ) and not necessarily those of SAE. The author is solely responsible for the content of th e paper. A process is available by which discussions will be printed with the pap er if it is publishe d in SAE Transactions. Persons wishing to submit papers to be considered for presentation or publicat ion by SAE should send the manuscript or a 300 word abstract to Se cretary, Engineering Meetings Board, SAE. Printed in USA 2006-01-1338 Hybrid System Development for a High-Performance Rear Drive Vehicle Kensuke Kamichi, Kazuomi Okasaka, Mamoru Tomatsuri, Takuji Matsubara, Yasuhiro Kaya and Hiroki Asada Toyota Motor Corp. Copyright © 2006 SAE International ABSTRACT The original Toyota Hybrid System (THS) was installed in the Prius and was introduced in 1997 as the world’s first mass-produced hybrid passenger car. THS has been continuously improved. In 2003 THS-II (marketed as Hybrid Synergy Drive [HSD]), was installed in a new larger Prius. In 2005 HSD was installed in two SUVs: the RX400h and Highlander Hybrid. This system achieved both V8 engine power performance and compact class fuel economy with outstanding emissions performance. In 2006, the HSD line-up is expanded to front-engine rear-wheel (FR) drive in the Lexus GS450h. This paper will explain this hybrid system which achieves both 4.5-liter class power performance and compact class fuel economy, while meeting the most stringent emission standard SULEV. INTRODUCTION Environmental problems, such as global warming caused by worldwide increase in CO 2 emissions, and urban air contamination caused by other air pollutants, demand development of vehicles with improved emissions performance. The hybrid system, which combines an internal-combustion engine and an electric motor, is recognized as highly effective in reducing emissions of CO 2 and criteria air pollutants. In 1997, the Toyota Hybrid System (THS) was installed in the world’s first mass-production hybrid vehicle, the Prius. It proved to be far superior in both fuel efficiency and environmental performance to the conventional gasoline-engine vehicles. Through a succession of improvements, the original THS evolved into THS-II (marketed as HSD) and was installed in the new Prius.It achieved outstanding superiority in fuel efficiency, CO 2 emission reduction and power performance. In 2005, with further improvements, the HSD line-up expanded to include mid-size SUVs and it was mounted in the RX400h and the Highlander. This enhanced HSD power train has excellent environmental and