Your Selections

REPSOL SA
Show Only

Collections

File Formats

Content Types

Dates

Sectors

Topics

Authors

Publishers

Affiliations

Events

   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Real World Fleet Test to Determine the Impact of Lower Viscosity Engine Oils from Heavy-Duty CNG and Diesel Buses. Part II: Oil Performance

REPSOL SA-Tomás Pérez
Universitat Politècnica de València-Bernardo Tormos, Guillermo Miró, Leonardo Ramirez
Published 2017-10-08 by SAE International in United States
Low viscosity engine oils are considered a feasible solution for improving fuel economy in internal combustion engines (ICE). So, the aim of this study was to verify experimentally the performance of low viscosity engine oils regarding their degradation process and possible related engine wear, since the use of low viscosity engine oils could imply higher degradation rates and/or unwanted wear performance. Potential higher wear could result in a reduction in life cycle for the ICE, and higher degradation rates would be translated in a reduction of the oil drain period, both of them non-desired effects. In addition, currently limited data are available regarding “real-world” performance of low viscosity engine oils in a real service fleet.In this particular case, there were included out-of-the European Automobile Manufacturers' Association (ACEA) oil specifications in terms of HTHS dynamic viscosity, where low viscosity was considered (3.0 mPa·s), making this test highly interesting for industry. On this test, 49 buses were monitored using a deep and extensive oil analysis program, comprising two engine technologies (Diesel and CNG), four engine types and…
This content contains downloadable datasets
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Real World Fleet Test to Determine the Impact of Low Viscosity Engine Oils from Heavy-Duty CNG and Diesel Buses - Part I: Fuel Consumption

REPSOL SA-Tomás Pérez
Universitat Politècnica de València-Bernardo Tormos, Leonardo Ramirez, Guillermo Miró
Published 2017-10-08 by SAE International in United States
One of the most interesting alternatives to reduce friction losses in the internal combustion engines is the use of low viscosity engine oils. Recently, a new engine oil category focused fuel economy, has been released in North America encouraging the use of these oils in the heavy-duty vehicles’ segment. This paper presents the results of a comparative test where the differences in fuel consumption given by the use of these oils are shown. The test included 48 buses of the urban public fleet of the city of Valencia, Spain. The selected vehicles were of four different bus models, three of them fueled with diesel and the other one with compressed natural gas (CNG). Buses’ fuel consumption was calculated on a daily basis from refueling and GPS mileage. After three oil drain intervals (ODI), the buses using low viscosity engine oils presented a noticeable fuel consumption reduction. These results bear out the suitability of these oils to palliate engine inefficiencies.
This content contains downloadable datasets
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Effect of Octane Number on the Performance of Euro 5 and Euro 6 Gasoline Passenger Cars

REPSOL SA-Maria Dolores Cardenas
BP International Ltd.-John Williams
Published 2017-03-28 by SAE International in United States
Research Octane Number (RON) and Motor Octane Number (MON) are used to describe gasoline combustion which describe antiknock performance under different conditions. Recent literature suggests that MON is less important than RON in modern cars and a relaxation in the MON specification could improve vehicle performance. At the same time, for the same octane number change, increasing RON appears to provide more benefit to engine power and acceleration than reducing MON. Some workers have advocated the use of an octane index (OI) which incorporates both parameters instead of either RON or MON to give an indication of gasoline knock resistance. Previous Concawe work investigated the effect of RON and MON on the power and acceleration performance of two Euro 4 gasoline passenger cars during an especially-designed acceleration test cycle. A large number of fuels blended with and without oxygenates and ranging from around 95 to 103 RON and sensitivities (RON minus MON) up to around 15 were tested. The results were vehicle dependent but in general, showed that sensitivity and octane index appear to be…
This content contains downloadable datasets
Annotation ability available