400 Commonwealth Drive, Warrendale, PA 15096-0001 U.S.A. Tel: (724) 776-4841 Fax: (724) 776-5760 Web: www.sae.orgSAE TECHNICAL PAPER SERIES 2004-01-1086 Study on Fuel Economy and NOx Emissions of Medium Duty Hybrid Truck in Real Traffic Conditions Yutaka Takada, Shigeru Ueki and Akira Saito Organization for the promotion of low emission vehicles (LEVO) Reprinted From: General Emissions 2004 (SP-1863) 2004 SAE World Congress Detroit, Michigan March 8-11, 2004Downloaded from SAE International by University of British Columbia, Monday, July 30, 2018All 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: permissions@sae.orgFax: 724-772-4891Tel: 724-772-4028 For multiple print copies contact: SAE Customer ServiceTel: 877-606-7323 (inside USA and Canada)Tel: 724-776-4970 (outside USA)Fax: 724-776-1615Email: Customer Service@sae.org ISBN 0-7680-1319-4Copyright © 2004 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 the 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 publication by SAE should send themanuscript or a 300 word abstract of a proposed manuscript to: Secretary, Engineering Meetings Board, SAE. Printed in USADownloaded from SAE International by University of British Columbia, Monday, July 30, 20182004-01-1086 Yutaka Takada, Shigeru Ueki and Akira Saito Organization for the promotion of low emission vehicles (LEVO) Copyright © 2004 SAE International ABSTRACT Hybrid trucks have now started to penetrate the Japanese market. To investigate their advantages for fuel economy and exhaust emissions, a real time on-board measurement system for fuel economy and NOx emissions was mounted in a medium duty hybrid truck with a capacitor system. Running tests were carried out with various payloads on roads. The results demonstrated the advantages of the hybrid truck in real traffic conditions. Fuel economy was improved on urban and suburban roads, as compared to a base diesel vehicle. The hybrid truck showed less NOx emissions during acceleration at starting, whereas, acceleration of diesel vehicles may cause intensive localized NOx pollution of roadsides, in pl aces like intersections. In order to fully demonstrate the advantages of the tested hybrid truck, it was important not to use running conditions with infrequent stops, such as those on a highway, or running conditions in which less brake energy recovery can take place, such as those in a traffic jam, where it is hard to recover brake energy even though frequent stops occur. In addition, further reduction of NOx might be obtained by optimizing engine operation in the diesel engine running mode of the hybrid truck. INTRODUCTION Low emission vehicles have been introduced as a result of growing consciousness regarding air pollution caused by automobile exhaust emissions in big cities. In this context, heavy duty city buses using hybrid technology, which aim at low fuel economy and low emissions, have started to be practically used [1][2][3]. In recent years, hybrid trucks have also been developed and adopted for business vehicles [4][5], although it is desirable to reduce their cost for further popularization. As hybrid vehicles improve fuel economy and exhaust emissions through recovery of brake energy, their effectiveness depends on running conditions. In the case of trucks, as compared to city buses which run a scheduled service route, there are many types of real traffic condition in