Designation:D6681−15StandardTestMethodforEvaluationofEngineOilsinaHighSpeed,Single-CylinderDieselEngine—Caterpillar1PTestProcedure1ThisstandardisissuedunderthefixeddesignationD6681;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.INTRODUCTIONAnyproperlyequippedlaboratorywithoutoutsideassistancecanusethetestmethoddescribedinthisstandard.However,theASTMTestMonitoringCenter(TMC)2providescalibrationoilsandanassessmentofthetestresultsobtainedonthoseoilsbythelaboratory.Bythismeansthelaboratorywillknowwhethertheiruseofthetestmethodgivesresultsstatisticallysimilartothoseobtainedbyotherlaboratories.Furthermore,variousagenciesrequirethatalaboratoryutilizetheTMCservicesinseekingqualificationofoilsagainstspecifications.Forexample,theU.S.Armyhassucharequirementinsomeofitsengineoilspecifications.Accordingly,thistestmethodiswrittenforthoselaboratoriesthatusetheTMCservices.LaboratoriesthatchoosenottousetheseservicesshouldignorethoseportionsofthetestmethodthatrefertotheTMC.InformationLettersissuedperiodicallybytheTMCmaymodifythismethod.3Inaddition,theTMCmayissuesupplementarymemorandarelatedtothetestmethod.1.Scope*1.1ThistestmethodcoversandisrequiredtoevaluatetheperformanceofengineoilsintendedtosatisfycertainAmericanPetroleumInstitute(API)Cservicecategories(includedinSpecificationD4485).Itisperformedinalaboratoryusingastandardizedhigh-speed,single-cylinderdieselengine.4Pistonandringgroovedeposit-formingtendencyandoilconsumptionismeasured.Thepiston,therings,andthelinerarealsoexaminedfordistressandtheringsformobility.1.2ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.1.2.1Exceptions—WherethereisnodirectSIequivalentsuchasscrewthreads,NationalPipeThreads/diameters,tubingsize,orwherethereisasolesourcesupplyequipmentspecificati...
