Fuel Economy Engine Oils: Scientific Rationale and Controversies
- Delivery
- Provide download link
- Format
- Price
- Non-members (tax incl.)：￥6,600 Members (tax incl.)：￥5,280
- Paper/Info type
- SAE Paper
No.2021-24-0067
- Pages
- 1-9(Total 9 p)
- Date of publication
- Sep 2021
- Publisher
- SAE International
- Language
- English
- Event
- International Conference on Engines and Vehicles 2021
Detailed Information
| Author(E) | 1) Boris Zhmud, 2) Arthur Coen, 3) Karima Zitouni |
|---|---|
| Affiliation(E) | 1) BIZOL Germany GmbH, 2) OLEON France, 3) OLEON France |
| Abstract(E) | 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. However, development of a balanced formulation is not as straightforward as it appears, and numerous pitfalls may be encountered due to additive interactions. Another serious problem is that the definition of “fuel-economy engine oil” is rather vague, as it depends on choice of reference oil. Nowadays, the assessment of fuel economy is often 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 heavily boosted low-displacement engines. Hence, many OEM-specific fuel economy tests also exist and different engine designs often produce controversial results. 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 customer expectations. |
