SHEARSTABILITYOFMULTIGRADEENGINEOILSInstituteofPetroleumFleetTestsPreparedbytheDataAnalysisPanelofASTMCommitteeD-2ResearchandDevelopmentDivisionVIIBontheShearStabilityofFluidsASTMDATASERIESPUBLICATIONDS49S-lListprice$4.0005-049001-12*AMERICANSOCIETYFORTESTINGANDMATERIALS1916RaceStreet,Philadelphia,Pa.19103©BYAMERICANSOCIETYFORTESTINGANDMATERIALSLibraryofCongressCatalogCardNumber:74-80697NOTETheSocietyisnotresponsible,asabody,forthestatementsandopinionsadvancedinthispublication.PrintedinGibbsboro,N.J.June1974-1-I.SUMMARYTwocarfleetprogramssponsoredbytheInstituteofPetroleum(I.P.)wereconductedontenASTMReferenceOilsaspartofanASTMprogramtostudymethodsofevaluatingtheshearstabilitycharacteristicsofpolymercontainingoils.Theresultsobtainedfromonefleetconsistingofconventionalcars,i.e.,carshavingseparateoilchargesfortheirenginesandtheirgearboxes,agreedwellwiththeaverageresultsfromsixU.S.carfleets.Asecondfleet,madeupofcarshavingacommonoilchargeforthegearboxesandtheenginecrankcases,shearedthereferenceoilssubstantiallymorethantheotherfleets.Viscositylossresultsfromthesecondfleetcorrelatedpoorlywiththosefromallshearstabilitybenchtestsandwithresultsfromtheotherfleets.II.INTRODUCTIONANDBACKGROUNDIn1969,ASTMR&DDiv.VIIB-lSubsectionontheshearstabilityofcrankcaseoilsinitiatedaprogram"tostudywaysofevaluatingtheshearstabilityofpolymer-containingoilsunderconditionscloselyrelatedtoservice".Sincethen,13ASTMReferenceOils(ARO's)wereformulatedandevaluatedinsixUnitedStatescarfleetsandinavarietyofbenchtests.TheseresultsaresummarizedinASTMdataseriesreport,DS49,publishedinearly1973.'*ThecurrentreportsummarizesdatafromtwofleetswhichwereusedintestsconductedbytheInstituteofPetroleummembersrecently.Onefleetwasmadeupofcarswhichusedthesameoilchargeinboththeengineandthetrans-mission(hereafterreferredtoasintegralgearboxcars).Theotherfleetwasofconventionaldesign.Bothfleetshadsevencarsandeachfleetevaluatedsevenofthe13ARO'salthoughthesevenwerenotthesameoilsineachcase.*Numbersinparenthesesdesignatereferenc...
