400 Commonwealth Drive, Warrendale, PA 15096-0001 U.S.A. Tel: (724) 776-4841 Fax: (724) 776-0790 Web: www.sae.org SAE TECHNICAL PAPER SERIES 2007-01-3974 Design and Performance of Low-Viscosity ATF Isao Kurihara and Osamu Kurosawa Nippon Oil Corporation Powertrain & Fluid Systems Conference & Exhibition Rosemont, Illinois October 29-November 1, 2007Downloaded from SAE International by University of British Columbia, Sunday, July 29, 2018The Engineering Meetings Board has approved this paper for publication. It has successfully completed SAE's peer review process under the supervision of the session organizer. 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 © 2007 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 paper if it is published in SAE Transactions. Persons wishing to submit papers to be considered for presentation or publication by SAE should send the manuscript or a 300 word abstract to Secretary, Engineering Meetings Board, SAE. Printed in USADownloaded from SAE International by University of British Columbia, Sunday, July 29, 20182007-01-3974 Design and Performance of Low-Viscosity ATF Isao Kurihara and Osamu Kurosawa Nippon Oil Corporation Copyright © 2007 SAE Inter national ABSTRACT Low-viscosity automatic transmission fluids (ATF) have advantages in terms of lower churning losses and lower drag resistance in the automatic transmission (AT) and higher transmission efficiency. While a low viscosity is effective to the improvement of fuel economy, there is a risk of degraded fatigue prevention performances or anti-wear properties of the ATF, which can have an adverse effect on the reliability of the AT. Consequently, the use of current low-viscosity ATFs were limited to AT units that were specially developed to use them. The aim of our study was to resolve these problems and improve the general versatility of low-viscosity ATFs. We developed a low-viscosity ATF having high reliability by designing its viscosity based on the field test data involving conventional commercial fluids of normal viscosity design (7.4mm 2/s@100°C), and by optimizing the blend of base stocks and viscosity index improv ers (VI improvers). Various laboratory tests and DEXRON® specification tests showed that the newly developed low-viscosity ATF provides fatigue resistance and anti-wear protection as good or better than conventional ATF. Moreover, this developed ATF showed better fuel economy than a conventional ATF in fuel economy tests using a chassis dynamometer. INTRODUCTION With growing concern over global warming and stricter government-mandated fuel economy standards, the circumstances surrounding the auto industry are changing dramatically. Consequently, calls for more eco-friendly automotive technologies grow louder by the year. In Japan, the transportation sector accounts for roughly 20% of the country’s CO 2 emissions. Estimates indicate that roughly half this amount comes from passenger cars. Since the April 2005 announcement of the “Plan to Meet the Kyoto Target”, which sets rates for cutting greenhouse gases, Original Equipment Manufacturers (OEM) have conc