Fuel Economy Engine Oils: Scientific Rationale and Controversies BIZOL Germany GmbH

Format:

Book

Conference/Event

Author/Creator:

Zhmud, Boris, author.

Contributor:

Coen, Arthur

Zitouni, Karima

Conference Name:

15th International Conference on Engines & Vehicles (2021-09-12 : Capri, Italy)

Language:

English

Physical Description:

1 online resource cm

Place of Publication:

Warrendale, PA SAE International 2021

Summary:

Since a significant part of energy losses in the internal combustion engine comes from viscous dissipation, the trend has shifted toward low-viscosity oils from SAE 40 and 50 in the 1960s-1980s to current SAE 20 and lower viscosity grades. Use of low viscosity engine oils significantly reduces energy losses in the main bearing and piston/bore systems, while tribological stresses on the valvetrain - especially in flat-tappet cammed engines - may increase. This makes a strong argument for deploying new classes of friction modifiers and antiwear additives. This communication summarizes authors' experience with the development of resource-conserving lubricants. It shows that the development of balanced formulations is not as straightforward as it appears, and numerous pitfalls may be encountered due to additive interactions. A special emphasis is made on the use of various classes of friction modifiers in lubricant formulations. Another discussion point is how the fuel economy effect of lubricants is measured. A serious problem here is that the definition of "fuel-economy engine oil" is rather vague, as it depends on choice of reference oil. At the moment, the assessment of fuel economy is based on the Sequence VIE or VIF tests using a 2012 3.6L GM V6 gasoline engine. It is not unexpected that the results of this test turn to be largely misleading when extrapolated to modern boosted small displacement engines, in particular those used in hybrid vehicles. Sequence VI, in its current implementation, is also not suitable for evaluation of ultralow viscosity grades, such as SAE 0W-12 and 0W-8. A new test protocol introduced with the Japanese JASO GLV-1 specifications will be discussed. Furthermore, the "fuel economy" performance of the same oil in the same engine may change dramatically depending on the driving cycle. All the aforesaid circumstances are to be taken into account when trying to harmonize normative performance claims with technical rationality and customer expectations

Notes:

Vendor supplied data

Publisher Number:

2021-24-0067

Access Restriction:

Restricted for use by site license