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 2008-01-1728 A New Automatic Transmission Fluid with Extended Friction Durability and Minimal Temperature Dependence Samuel H. Tersigni, Lee D. Saathoff, Christopher S. Cleveland and Hong-Zhi Tang Afton Chemical Corporation Mark S. Jones Afton Chemical Limited Kenji Yatsunami Afton Chemical Japan Corporation 2008 SAE Internati onal Powertrains, Fuels and Lubricants Congress Shanghai, China June 23-25, 2008Downloaded from SAE International by Univ of Nottingham - Kings Meadow Campus, Monday, September 10, 2018By mandate of the Engin eering Meetings Board, th is paper has been approved for SAE publication upon completion of a peer review process by a minimum of three (3) industry experts under the supervision of the session organizer. 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: permissions@sae.orgTel: 724-772-4028Fax: 724-776-3036 For multiple print copies contact: SAE Customer ServiceTel: 877-606-7323 (inside USA and Canada)Tel: 724-776-4970 (outside USA)Fax: 724-776-0790Email: Customer Service@sae.org ISSN 0148-7191Copyright © 2008 SAE InternationalPositions 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 Univ of Nottingham - Kings Meadow Campus, Monday, September 10, 20181 Copyright © 2008 SAE International ABSTRACT This laboratory presents a new step-automatic transmission fluid with en hanced friction durability and robustness for the Asian marketplace. This mineral-oil- based fluid also meets JASO M315-1A performance requirements on torque capacity, anti-oxidation, anti- wear, extreme pressure (EP), anti-aeration/foam control, copper corrosion and anti-rust performance. The fluid offers a JASO M349 low velocity friction apparatus (LVFA) durability lifetime of over 1100 hour s. Moreover, this fluid maintains stable torque capacity during its entire LVFA durability lifetim e, across the temperature range of 40 to 120 ̊C. Similarly, friction level changes with sliding speed are smaller than experienced by other commercial factory-fill ATFs. These critical performance features are due to a new fluid friction system approach, which may enable new types of transmission hardware or calibration. INTRODUCTION Automobile manufacturers receive corporate average fuel economy (CAFE) benefits by employing low viscosity automatic transmission fluids (ATFs), which reduce the churning losses and drag resistance in the automatic transmission (AT) [1-7]. The new generation of ATF has a fresh oil kinem atic viscosity at 100 ˚C (KV100˚C) between 5.2 and 6.4 cSt [1-7], which leads to lower Brookfield and start-up viscosities. Low viscosity ATFs, however, can be a challenge to the transmission hardware [6, 7], especially with respect to fluid losses in pumps, and gear and bearing protection. One estimate of the thickness (FT) of protective lubricating films is a function of sliding speed (v) and fluid viscosity ( ŋ) (FT = k x v 0.67 x ŋ0.67, where k is a constant) [8]. Note, a lower viscosity ATF leads to thinner protective films for bearings, clutches and gears, unless f