ISSN: 1546-962X
Published Online: 6 December 2007
Page Count: 13

No/Low SAP and Alternative Engine Oil Development and Testing
Woydt, Mathias
Federal Institute for Materials Research and Testing (BAM), Berlin

(Received 12 January 2007; accepted 1 November 2007)

Abstract

The use of alternative base oils, like esters or polyglycols, with more intrinsic properties for the lubrication of automobile engines has a potential for ecological and technical advantages. Being in competition with hydrocarbon-based formulations, detailed knowledge of several thermophysical and viscometric properties as well as tribological properties over a large temperature range are required (mapping). The tested polymer-free polyglycols and ester-based formulations displayed no visible tribological weaknesses regarding wear resistance and EP-behavior as well as offering significant advantages in order to meet metal- and ash-free and bio-no-tox criteria. Especially the formulated polyglycols without friction modifiers also showed an intrinsic retention of low coefficients of friction and a hydrodynamic film forming behavior comparable to hydrocarbon-based factory-fill oils. The wear resistance and EP-behavior of low-additivated polyglycols, but also of esters, can be enhanced by means of triboactive materials. Lubricious oxides or triboactive materials and polar base oils, or a combination thereof, may substitute the EP and AW properties realized by the additives, thus enabling long drains and responding to “eco-tox” or “bio-no-tox” requirements as well as restrictions from the “chemical box.”

Keywords:
ester, polyglycol, PAG, PPG, factory fill, hydrocarbon, engine oil, bio-oils, eco-lubricants, EAL, bio-no-tox oils, heat capacity, density, viscosity, pressure-viscosity, thermal conductivity, mixed, boundary, lubrication, low sap, mid sap, wear, friction, triboactive materials

Paper ID: JAI100898
DOI: 10.1520/JAI100898
ASTM International is a member of CrossRef.