Designation:D6891−21´1StandardTestMethodforEvaluationofAutomotiveEngineOilsintheSequenceIVASpark-IgnitionEngine1ThisstandardisissuedunderthefixeddesignationD6891;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.ε1NOTE—EditoriallyupdatedTMCgovernanceinformationinJune2022.INTRODUCTIONPortionsofthistestmethodarewrittenforusebylaboratoriesthatmakeuseofASTMTestMonitoringCenter(TMC)2services(seeAnnexA1).TheTMCprovidesreferenceoils,andengineeringandstatisticalservicestolaboratoriesthatdesiretoproducetestresultsthatarestatisticallysimilartothoseproducedbylaboratoriespreviouslycalibratedbytheTMC.Ingeneral,theTestPurchaserdecidesifacalibratedteststandistobeused.OrganizationssuchastheAmericanChemistryCouncilrequirethatalaboratoryutilizetheTMCservicesaspartoftheirtestregistrationprocess.Inaddition,theAmericanPetroleumInstituteandtheGearLubricantReviewCommitteeoftheLubricantReviewInstitute(SAEInternational)requirethatalaboratoryusetheTMCservicesinseekingqualificationofoilsagainsttheirspecifications.TheadvantageofusingtheTMCservicestocalibrateteststandsisthatthetestlaboratory(andhencetheTestPurchaser)hasanassurancethattheteststandwasoperatingattheproperleveloftestseverity.Itshouldalsobeborneinmindthatresultsobtainedinanon-calibratedteststandmaynotbethesameasthoseobtainedinateststandparticipatingintheASTMTMCservicesprocess.LaboratoriesthatchoosenottousetheTMCservicesmaysimplydisregardtheseportions.1.Scope*1.1Thistestmethodmeasurestheabilityofcrankcaseoiltocontrolcamshaftlobewearforspark-ignitionenginesequippedwithanoverheadvalve-trainandslidingcamfollowers.Thistestmethodisdesignedtosimulateextendedengineidlingvehicleoperation.TheSequenceIVATestMethodusesaNissanKA24Eengine.Theprimaryresultiscamshaftlobewear(measuredatsevenlocationsaroundeachofthetwelvelobes).Secondaryres...
