Zero wear concept using bionotox and polymer‐free engine oils with triboactive materials

Abstract

PurposeThe purpose of this paper is to underline the future need for OEMs to receive lowSAP, polymer‐ and metal‐free engine oils with high‐viscosity indices and to illuminate for other OEMs the technical feasibility for application of alternative engine oils based on esters or blends of hydrocarbons with esters or polyglycols.Design/methodology/approachThe strategic goal depends technically on the use of intrinsic properties of alternative base fluids, thus substituing some additives, like anti‐wear, extreme pressure and viscosity index improvers. The prone wear resistance of novel triboactive/‐reactive materials enables higher portions of mixed/boundary lubrication generated by oils with a lower viscosity.FindingsOverall, the different bionotox and low‐ash prototype engine oils with reduced additive contents displayed isoperformance regarding the tribological behaviour against cast iron and triboreactive materials. APS‐Tin−2Cr2O2n−1 displayed an overall wear resistance comparable with grey cast iron with high‐carbon content and liner wear reduction of one order of magnitude when mated with Mo‐based rings. Both tests confirmed the potential for substituing molybdenum‐based rings by APS‐Tin−2Cr2O2n−1. The most significant reduction in “system wear” down to “zero wear” was demonstrated by mating the APS‐Tin−2Cr2O2n−1 coated piston rings with smooth machined HVOF‐(Ti,Mo)(C,N) liner coatings.Research limitations/implicationsAs lubricants are today not part of the core business of automotive OEMs, the next steps have to be proposed by the petrochemical suppliers. It is recalled here that some OEMs in their history developed and produced lubricants.Practical implicationsThe customer will appreciate any increase in longevity resulting in reduced maintenance. The OEM now owns, under increased solicitations, now a future‐oriented tool box in order to respond to environmental and CAFÉ demands with reasonable cost management.Originality/valueThis OEM report displays the complete methodology in order to adopt alternative engine oils in existing engine architectures.