SAE TECHNICAL PAPER SERIES 982666 High Quality Base Oils for Next Generation Automatic Transmission Fluids H. E. Henderson and B. Swinney Petro-Canada Lubricants Reprinted From: Automatic Transmission Fluids (ATF) (SP-1394) eA E The Engineering Society For Advancing Mobility Land Sea Air and Space, INTERNATIONALInternational Fall Fuels and Lubricants Meeting and Exposition San Francisco, California October 19922,1998 400 Commonwealth Drive, Warrendale, PA 15096-0001 U.S.A. Tel: (724) 776-4841 Fax: (724) 776-5760Downloaded from SAE International by Purdue University, Sunday, August 19, 2018The appearance of this ISSN code at the bottom of this page indicates SAE’s consent that copies of the paper may be made for personal or internal use of specific clients. This consent is given on the condition,however, that the copier pay a $7.00 per article copy fee through the Copyright Clearance Center, Inc.Operations Center, 222 Rosewood Drive, Danvers, MA 01923 for copying beyond that permitted by Sec-tions107or108oftheU.S.CopyrightLaw.Thisconsentdoesnotextendtootherkindsofcopyingsuchascopying for general distribution, for advertising or promotional purposes, for creating new collective works,or for resale. SAE routinely stocks printed papers for a period of three years following date of publication. Direct your orders to SAECustomer Sales andSatisfactionDepartment. Quantity reprint rates canbeobtained from the Customer Sales andSatisfactionDepartment.To request permission to reprint a technical paper or permission to use copyrighted SAE publications in other works, contact theSAE Publications Group. No part of this publication may be reproduced in any form, in an electronic retrieval system or otherwise, without the prior written permission of thepublisher. ISSN 0148-7191 Copyright © 2000Society ofAutomotiveEngineers, Inc. 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 inSAE Transactions. For permissiontopublish this paper in full orin part, contact the SAE Publications Group. Persons wishing to submit papers to be considered for presentation or publication through SAE should send the manuscript or a 300 word abstract of a proposed manuscript to: Secretary, Engineering Meetings Board, SAE. P ri nte di nU SAAll SAE papers, standards, and selected books are abstracted and indexed in theGlobalMobility DatabaseDownloaded from SAE International by Purdue University, Sunday, August 19, 2018High Quality Base Oils for Next Generation Automatic Transmission Fluids H. E. Henderson and B. Swinney Petro-Canada Lubricants Copyright 0 1998 Society of Automotive Engineers, Inc. ABSTRACT Significant changes are occurring in the development of automatic transmission fluids (ATF) which impact the selection of both additive components and lubricant base oils. In particular, the need for improved viscometrics at high and low temperatures, combined with the need for increased oxidation performance and shear stability are moving formulators towards use of higher quality API Group II (100 - 120 VI) and/or Group III base oils. Several benefits are apparent with the use of API Group III base oils in ATF. Their naturally high Viscosity Index of >120 provides opportunities to use a higher base oil viscosity compared to API Group I and in many instances Group II base oils. This reduces the amount of Viscosity Modifier in the finished ATF and improves overall shear stability. Higher kinematic viscosity also improves volatility which leads to improved oxidation resistance. Low temperature fluidity can be improved by modifying the amount and type of residual wax in the base oil. This is achieved through two main factors, namely: (i) feed selection and (ii) the type of dewaxing process, isodewaxing being preferred to conve