The Effects of Engine Oil Viscosity and Composition on Fuel Efficiency

1984 ◽  
Author(s):  
J. E. Clevenger ◽  
D. C. Carlson ◽  
W. M. Kleiser

2020 ◽  
Vol 13 (2) ◽  
pp. 131-150 ◽  
Author(s):  
Adam Agocs ◽  
Serhiy Budnyk ◽  
Charlotte Besser ◽  
Andjelka Ristic ◽  
Marcella Frauscher ◽  
...  

Lubricant degradation by additive depletion, contamination and build-up of degradation products deteriorates lubrication performance. It can be expected that engine oil degradation also has an impact on performance parameters. Engine development tends to higher power density, lower engine oil viscosity to optimize fuel efficiency, which heavily stress engine oils and thus demand increased oil performance. Correlations between engine oil degradation, friction and wear during an engine oil’s lifetime are a valuable asset in engine development towards performance, longevity and cost reduction. Here, physical-chemical and tribological properties of engine oils collected from passenger cars were determined. The results revealed the deterioration of friction (loss of fuel efficiency) and wear (increasing loss of material) depending on mileage. Defined used engine oils were produced by artificial alteration in a large-scale device and showed a very good correlation with the field samples.



2021 ◽  
pp. 146808742110129
Author(s):  
Hidemi Ogihara ◽  
Takumi Iwata ◽  
Yuji Mihara ◽  
Makoto Kano

Internal combustion engines have been improved markedly in recent years through efforts to conserve resources, reduce emissions and improve fuel efficiency. In this regard, the authors have been working to reduce friction and improve the seizure properties of the crankshaft main journal and main bearing. These mechanical components of internal combustion engines incur large friction losses. In order to reduce friction, journals have been coated with a diamond-like carbon (DLC) coating, which has been reported to reduce friction in the fluid lubrication regime in recent years. Another current issue of journals and bearings is the need to improve seizure resistance. Therefore, these properties were evaluated for material combinations of aluminium alloy bearings and DLC-coated journals, which have low affinity. The results revealed that friction was reduced under a fluid lubrication regime and seizure resistance was improved under a mixed lubrication regime.





2021 ◽  
Author(s):  
Thijs Schasfoort ◽  
Zoe Fard ◽  
Torsten Gehrmann ◽  
Steffen Hollatz

Abstract This paper evaluates the benefits of an SAE 30 monograde stationary gas engine oil (SGEO) in comparison with SAE 40 monograde SGEOs with the focus on two main areas. First, to demonstrate and quantify the positive impact of lower viscosity on the fuel consumption rate, and second to demonstrate the faster lubrication of hard to reach points in the engine during startup. The current industry recognized fuel efficiency test methods for passenger car and on-road diesel engine sectors are not suitable for evaluating the fuel efficiency performance of a gas engine oil because of the significant differences in fuel type, engine operating conditions, and oil formulations. This paper, therefore, describes comparative studies of three different gas engine oils in a modern MAN E3262 E302 gas engine that was carefully adapted and fully instrumented. The performance of each oil with respect to fuel efficiency was assessed in an extensive program comprising endurance testing, stationary tests on various load/speed points and dynamic tests running the engine fired as well as non-fired (motored). Another part of the test program explores the lubrication of hard to reach points in the engine, e.g. valve guide. The paper describes how the SAE 30 monograde oil results in faster lubrication of these parts during startup in comparison with the SAE 40 oils.



Author(s):  
Luis San Andrés ◽  
Feng Yu ◽  
Kostandin Gjika

Engine oil lubricated (semi) floating ring bearing (S)FRB systems in passenger vehicle turbochargers (TC) operate at temperatures well above ambient and must withstand large temperature gradients that can lead to severe thermo-mechanical induced stresses. Physical modeling of the thermal energy flow paths and an effective thermal management strategy are paramount to determine safe operating conditions ensuring the TC component mechanical integrity and the robustness of its bearing system. On occasion, the selection of one particular bearing parameter to improve a certain performance characteristic could be detrimental to other performance characteristics of a TC system. The paper details a thermohydrodynamic model to predict the hydrodynamic pressure and temperature fields and the distribution of thermal energy flows in the bearing system. The impact of the lubricant supply conditions (pressure and temperature), bearing film clearances, oil supply grooves on the ring ID surface are quantified. Lubricating a (S)FRB with either a low oil temperature or a high supply pressure increases (shear induced) heat flow. A lube high supply pressure or a large clearance allow for more flow through the inner film working towards drawing more heat flow from the hot journal, yet raises the shear drag power as the oil viscosity remains high. Nonetheless, the peak temperature of the inner film is not influenced much by the changes on the way the oil is supplied into the film as the thermal energy displaced from the hot shaft into the film is overwhelming. Adding axial grooves on the inner side of the (S)FRB improves its dynamic stability, albeit increasing the drawn oil flow as well as the drag power and heat flow from the shaft. The predictive model allows to identify a compromise between different parameters of groove designs thus enabling a bearing system with a low power consumption.



2003 ◽  
Vol 3 (5) ◽  
pp. 562-568 ◽  
Author(s):  
B. Jakoby ◽  
M. Scherer ◽  
M. Buskies ◽  
H. Eisenschmid


Author(s):  
P. R. Norton ◽  
Gavin Pereira ◽  
Yue-Rong Li ◽  
Andreas Lachenwitzer ◽  
Masoud Kasrai ◽  
...  

The improvement of fuel consumption is an important driving force for research and development in the automobile industry in order to minimize greenhouse gas emissions as well as improving fuel economy. Aluminum alloys are a class of alternative materials that are being used to replace cast iron in motor components due to the concomitant weight savings which result in improved fuel efficiency, and cost savings. Our research focuses on these alternative Al-based alloys as well as traditional steel interfaces, and the protective films that form on the surfaces. Currently the zinc dialkyl-dithiophosphates (ZDDPs) have been used as engine oil additives for over 60 years. They are important chemically-active additives, known for their antioxidant and antiwear characteristics. ZDDPs are known to form a protective film (tribofilms) at rubbed surfaces, typically on iron containing metals surfaces commonly used in the automotive industry; however ZDDPs and the products formed are not well suited for the environment as they can readily poison the catalytic converters and their efficacy on Al-Si alloys is not well established.



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