Search Results

The objective of this project was to assess the effects of various blends of biodiesel on locomotive engine exhaust emissions. Systematic, credible, and carefully designed and executed locomotive fuel effect studies produce statistically significant conclusions are very scarce, and only cover a very limited number of locomotive models. Most locomotive biodiesel work has been limited to cursory demonstration programs. Of primary concern to railroads and regulators is understanding any exhaust emission associated with biodiesel use, especially NOX emissions. In this study, emissions tests were conducted on two locomotive models, a Tier 2 EMD SD70ACe and a Tier 1+ GE Dash9-44CW with two baseline fuels, conventional EPA ASTM No. 2-D S15 (commonly referred to as ultra-low sulfur diesel - ULSD) certification diesel fuel, and commercially available California Air Resource Board (CARB) ULSD fuel.

By 2014, all new on- and off-highway diesel engines in North America, Europe and Japan will employ diesel particulate filters (DPF) in the exhaust in order to meet particulate emission standards. If the pressure across the DPF increases due to incombustibles remaining after filter regeneration, the exhaust backpressure will increase, and this in turn reduces fuel economy and engine power, and increases emissions. Due to engine oil consumption, over 90% of the incombustibles in the DPF are derived from inorganic lubricant additives. These components are derived from calcium and magnesium detergents, zinc dithiophosphates (ZnDTP) and metal-containing oxidation inhibitors. They do not regenerate as they are non-volatile metals and salts. Consequently, the DPF has to be removed from the vehicle for cleaning. Ashless oil could eliminate the need for cleaning.

Conventional diesel fuel has been in the market for decades and used successfully to run diesel engines of all sizes in many applications. In order to reduce emissions and to foster energy source diversity, new fuels such as alternative and renewable, as well as new fuel formulations have entered the market. These include biodiesel, gas-to-liquid, and alternative formulations by states such as California. Performance variations in fuel economy, emissions, and compatibility for these fuels have been evaluated and debated. In some cases contradictory views have surfaced. “Sustainable”, “Renewable”, and “Clean” designations have been interchanged. Adding to the confusion, results from one fuel in one type of engine such as an older heavy-duty engine, is at times compared to that of another fuel in another type such as a modern light-duty engine. This study was an attempt to compare the performance of several fuels in identical environments, using the same engine, for direct comparison.

Conventional diesel fuel has been in the market for decades and used successfully to run diesel engines of all sizes in many applications. In order to reduce emissions and to foster energy source diversity, new fuels such as alternative and renewable, as well as new fuel formulations have entered the market. These include biodiesel, gas-to-liquid, and alternative formulations by states such as California. Performance variations in fuel economy, emissions, and compatibility for these fuels have been evaluated and debated. In some cases contradictory views have surfaced. “Sustainable”, “Renewable”, and “Clean” designations have been interchanged. Adding to the confusion, results from one fuel in one type of engine such as an older heavy-duty engine, is at times compared to that of another type such as a modern light-duty. This study was an attempt to compare the performance of several fuels in an identical environment, using the same engine, for direct comparison.

Conventional diesel fuel (1) has been on the market for decades and used successfully to run diesel engines of all sizes in many applications.* In order to reduce emissions and to foster energy source diversity, new fuels such as alternative and renewable, as well as new formulations, have entered the market. These include biodiesel, gas-to-liquid, and alternative formulations by states such as California. Performance variations in fuel economy, emissions, and compatibility for these fuels have been evaluated and debated. In some cases, contradictory views have surfaced. “Renewable” and “clean” designations have been interchanged. Adding to the confusion, results from one fuel in one type of engine, such as an older heavy-duty engine, is at times compared to that of another type, such as a modern light-duty engine.

This paper reports on a field test with 23 Volvo D12C non-exhaust gas recirculation diesel engines using the Diesel Particulate Filter (DPF), Selective Catalytic Reduction (SCR), and urea system with Ultra-Low-Sulfur-Diesel (ULSD). This combination will be used to meet the on-highway emission standards for U.S. 2010, Japan 2010, and Europe 2013. Because of future widespread use of DPF-SCR, this study reports on our field experience with this system, and focuses on enhancing our understanding of the incombustible materials which are collected in the DPF with API CJ-4 and API CI-4 PLUS oils. The average weight of incombustibles was lower in the trucks using API CJ-4 oils at 1.0% sulfated ash, than in those using API CI-4 PLUS oils at 1.4% sulfated ash. The difference in weight between the two groups was highly significant. Further, the weight of the incombustibles per kilometer substantially decreased with each subsequent cleaning within a truck.

Researchers and cooperative groups worldwide conducted research and developed several test methods to gauge the lubricity of diesel fuel. This was necessary because the more recent fuel specifications require a higher level of hydrotreating which in turn can result in a reduction of diesel fuel lubricity. An appropriate test method was needed to enable measures to restore fuel lubricity and to enable fuel suppliers to comply with the newly adopted diesel fuel lubricity specification. The current test method that is used by most regions of the world is the High Frequency Reciprocating Rig, HFRR. Although this test method was developed and selected by the ISO group originally, and is fundamentally the same, it has been adopted in slightly different forms by regions of the world. One common element in all forms of the test method is its poor precision when compared to test methods for other fuel properties.

Of all the performance tests in the current International Lubricant Standardization and Approval Committee (ILSAC) GF-3 and GF-4 categories, the Sequence IIIF and Sequence IIIG are among the most difficult for the formulator. The Sequence III engine dynamometer tests place a premium on oxidation, high-temperature deposits, and valve train wear control. Besides appearing in the North American Passenger Car Motor Oil (PCMO) specifications, the Sequence III is required for European gasoline engine oils, for American Petroleum Institute (API) diesel engine oil categories, and for base oil interchanges (BOI) among licensed engine oils. The ability to screen antioxidants for the Sequence III is of special interest for developers of engine oil technology. Antioxidants are the single most expensive component and the search for cost-effective oxidation control is among the top technical hurdles for the North American PCMO categories.

This oil category was driven by two new cooled exhaust gas recirculation (EGR) engine tests operating with 15% EGR, with used oil soot levels at the end of the test ranging from 6 to 9%. These tests are the Mack T-10 and Cummins M11 EGR, which address ring, cylinder liner, bearing, and valve train wear; filter plugging, and sludge. In addition to these two new EGR tests, there is a Caterpillar single-cylinder test without EGR which measures piston deposits and oil consumption control using an articulated piston. This test is called the Caterpillar 1R and is included in the existing Global DHD-1 specification. In total, the API CI-4 category includes eight fired-engine tests and seven bench tests covering all the engine oil parameters. The new bench tests include a seal compatibility test for fresh oils and a low temperature pumpability test for used oils containing 5% soot. This paper provides a review of the all the tests, matrix results, and limits for this new oil category.

Fleet customers demand reduced operating costs. This necessitates the development of engine oils which can provide maximum fuel economy and extended oil drains, while still maintaining engine durability. This is particularly important in diesel engines produced since October 1998. These engines use retarded timing to meet EPA's emission requirements and, as a consequence in some cases, generate high soot levels in the engine oil. Extended oil drains in 1995 Caterpillar 3406E and 1996 Detroit Diesel Series 60 engines found no statistical difference in fuel economy or wear between a synthetic SAE 5W-40 and an SAE 15W-40 using API Group II base stocks. Both oils had the same API CG-4/SJ quality level. Soot levels at oil drains of 40,000-50,000 miles (64,372 - 80,465 km) ranged from 0.5-1.2%.

API's Engine Oil Licensing and Certification System has implemented Provisional Licensing in response to a shortage of parts for the Sequence IIIE engine test. A Task Force delegated by the ASTM Sequence II/III Surveillance Panel was asked to develop a process, if appropriate, for the use of mathematical models as a substitute for the Sequence IIIE engine test. The Task Force tried to develop a fair and technically justifiable system for predicting engine oil performance based on models derived from existing engine test databases. The situation appeared to some to be the ideal application for initiating and proving a virtual test approach. In the end, others said the situation was too time-constrained or limited in scope. This paper describes some of the statistical, technical, and practical issues involved in specifying a process for virtual testing. Some perspectives on these issues as discussed in the Task Force effort are explored.