ASTM_DS62-1985.pdf

THE RELATIONSHIP BETWEEN HIGH-TEMPERATURE OILRHEOLOGYAND ENGINE OPERATION A STATUS REPORT Prepared by ASTM Task Force D02.07.0B TF/EC on the Correlation of High-Temperature Oil Rheology with Engine Performance.ASTM Sub-committee D02.07.0B on High-Temperature Rheology of Non-Newtonian Fluids,Committee D-2 on Petroleum Products and Lubricants.ASTM DATA SERIES DS 62 This document was revised and approved by ASTM Committees D02.07.0B TR/EC,D02.06.0B,and D02.06 on 4 Dec.1984 ASTM Publication Code Number(PCN)05-894000-12 1916 Race Street,Philadelphia,PA 19103 Library of Congress Cataloging-in-Publication Data ASTM Committee D-2 on Petroleum Products and Lubricants.Subcommittee 7B Task Force on the Correlation of HighTemperature Oil Rheology with Engine Performance.The relationship between high-temperature oil rheology and engine operation.(ASTM data series;DS 62)ASTM publication code number(PCN)05-894000-12.1.Lubricating oilsEffect of temperature on.2.Automobile Lubrication.3.Rheology.I.Title.II.Series:ASTM data series publication;DS 62.TL153.5.A75 1985 629.255 85-15747 ISBN 0-8031-0448-0 Copyright by AMERICAN SOCIETY FOR TESTING AND MATERIALS 1985 Library of Congress Catalog Card Number:85-15747 NOTE The Society is not responsible,as a body,for the statements and opinions advanced in this publication Printed in Mars,PA,Dec.1985 FOREWORD PURPOSE.The ASTM High-Temperature Rheology/Engine Correlation Task Force(ASTM D02.07.0B TF/EC)has written this status report in partial response to a Society of Automotive Engineers(SAE)request to develop a test method which incorporates high-temperature,high-shear rate viscometrics or other rheological characteristics to predict the per-formance of both single and multigrade(i.e.,both Newtonian and Vl-improved)engine oils in engine bearings and/or the ring and cylinder area(1).Although this report does not deal with the development of particular viscosity measurement techniques,it does have two specific ob-jectives which relate to this SAE request:(1)to summarize,and interpret,as necessary,all perti-nent published studies relating high-temperature oil rheology to selected measures of engine per-formance and durability,and(2)to suggest areas for possible future research needed to resolve any uncertainties which remain regarding the effects of oil rheological properties on these same engine operating factors.SCOPE.This review summarizes those available data which describe the effects of oil rheological properties on(1)the operating parameters(oil film thickness and load capacity of journal bearings),(2)the wear of engine components,and(3)the frictional characteristics and fuel economy of engines.These three subjects were selected for review because each is related to the specific areas of interest indicated in the SAE request.Furthermore,only high-temperature(that characteristic of warmed-up engine operation)engine performance is considered.Those engine performance parameters(cranking,pumping)which are associated with low-temperature operation are not within the scope of this review.Related ASTM Publications The Relationship Between Engine Oil Viscosity and Engine Performance(Part V and VI),STP 621-S4(1980),04-621040-12 The Relationship Between Engine Oil Viscosity and Engine Performance(Part IV),STP 621-S3(1978),04-621030-12 The Relationship Between Engine Oil Viscosity and Engine Performance(Part III),STP 621-S2(1977),04-621020-12 The Relationship Between Engine Oil Viscosity and Engine Performance(Part II),STP 621-S1(1977),04-621010-12 The Relationship Between Engine Oil Viscosity and Engine Performance(Part I),STP 621(1977),04-621000-12 Contents Overview 1 Recommendations 3 Introduction 4 OilRheology-7 Oil Rheological Models and Definitions 9 Oil Rheological Measurement Techniques 14 The Effect of Oil Rheology on Bearing Film Thickness and Load Capacity 15 Analytical Models and Predictions 16 Oil Film Thickness Measurements 20 Load Capacity Measurements 32 The Effect of Oil Rheology on Engine Wear 33 Journal Bearings 36 Journal Bearing Rig Studies 36 Engine Bearing Studies 36 Piston Ring and Cylinder 45 Valve Train 47 The Effect of Oil Rheology on Friction and Fuel Economy 49 Friction 52 Fuel Economy 59 Relationship to Kinematic Viscosity 59 Relationship to High-Temperature,High-Shear Viscosity 64 Discussion 73 Summation of Available Data 75 Technical Questions Remaining 78 Possible Future ASTM D02.07.OB TF/EC Efforts 79 References 81 ASTM D02.07.0BTF/EC Membership 92 ASTM D02.07.0B TF/EC Status Report Writing Committee 94 LIST OF TABLES Table Page I Critical High-Shear-Rate Viscosities 44 II Effective Viscosities of Multigrade Oils 53 III Power Loss Values in CEC CL23 Reference Oils 54 IV Fuel Economy Benefits With the Use of Low Viscosity Lubricants for Different Driving Cycles 59 V Viscometric Properties of Test Oils as a Function of SAE Grade 62 VI Effect of Viscosity on Fuel Economy 62 VII Viscosity Calibrations 140 CID(2.3 Liter)&305 CID(5.0 Liter)Engines 63 VIII Linear