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A test programme has been conducted to study any potential long term effects of gasoline sulphur on catalyst performance, using a newly developed transient engine-bed ageing cycle. The ageing cycle, which was based on repeated European Extra Urban Drive Cycles, was chosen to ensure that the catalyst experienced a realistically wide range of temperatures and space velocities, together with transients, idle and periods of overrun. Two nominally identical platinum/rhodium catalysts (manufactured from the same batch) with matched lambda sensors, were aged for a period of 80,000 km each, one being aged using a gasoline containing 50 mg/kg (ppm wt) sulphur, the other being aged on the same fuel doped to 450 ppm wt S. The emissions performance of both catalysts was measured after 6,000, 40,000 and 80,000 km ageing, by fitting the catalysts to a test vehicle, and performing emissions tests over the European test cycle at both sulphur levels.

In emerging markets, Port Fuel Injection (PFI) technology retains a higher market share than Gasoline Direct Injection (GDI) technology. In these markets fuel quality remains a concern even despite an overall improvement in quality. Typical PFI engines are sensitive to fuel quality regardless of brand, engine architecture, or cylinder configuration. One of the well-known impacts of fuel quality on PFI engines is the formation of Intake Valve Deposits (IVD). These deposits steadily accumulate over time and can lead to a deterioration of engine performance. IVD formation mechanisms have been characterized in previous studies. However, no test is available on a state-of-the-art engine to study the impact of fuel components on IVD formation. Therefore, a proprietary engine test was developed to test several chemistries. Sixteen fuel blends were tested. The deposit formation mechanism has been studied and analysed.

Previous studies have shown that regenerating particulate filters are very effective at reducing particulate matter emissions from diesel engines. Some particulate filters are passive devices that can be installed in place of the muffler on both new and older model diesel engines. These passive devices could potentially be used to retrofit large numbers of trucks and buses already in service, to substantially reduce particulate matter emissions. Catalyst-type particulate filters must be used with diesel fuels having low sulfur content to avoid poisoning the catalyst. A project has been launched to evaluate a truck fleet retrofitted with two types of passive particulate filter systems and operating on diesel fuel having ultra-low sulfur content. The objective of this project is to evaluate new particulate filter and fuel technology in service, using a fleet of twenty Class 8 grocery store trucks. This paper summarizes the truck fleet start-up experience.

A comparison of two different types of NOx reducing catalysts will be worked out. The potential of two De-NOx catalysts using engine out hydrocarbon emissions for NOx conversion will be shown by variation of different engine parameters. An analysis of the hydrocarbon species upstream and downstream catalyst will demonstrate, which components are responsible for the NOx reduction in the exhaust gas of a lean burn engine. By variation of different parameters during adsorbtion and regeneration phases of the adsorber catalyst the efficiency in NOx reduction will be optimized. An assessment of the suitability for lean burn engines will consider the emission reduction efficiency as well as the influence on engine fuel consumption.

The molecular filtration of sulfur components in ultra low sulfur diesel (ULSD) fuel is described. A comprehensive screening of potential sulfur removal chemistries has yielded a sorbent which has the capability to efficiently remove organo-sulfur components in ULSD fuel. This sorbent has been used to treat ULSD fuel on a heavy duty engine equipped with NOx adsorber after-treatment technology and has been shown to lengthen the time between desulfation steps for the NOx adsorber. The fuel properties, cetane number and aromatics content, etc., have not been changed by the removal of the sulfur in the fuel with the exception of the lubricity which is reduced.

Gasoline direct injection (GDI) engines have been developed rapidly in recent years, driven by stringent legislative requirements on vehicle fuel efficiency and emissions. However, one challenge facing GDI is the formation of particulate emissions, particularly with the presence of injector tip deposits. The Chinese market features some gasoline fuels that contain no detergent additives and are prone to deposit formation, which can affect engine performance and emissions. The use of detergent additives to mitigate the formation of injector deposits in a GDI engine was investigated in this study by testing a 1.5L turbocharged GDI engine available in the Chinese market. The engine was operated both on base gasoline and on gasoline dosed with detergent additives to evaluate the effect on injector deposit formation and engine performance and emissions.

This paper reports the test results from the DPF (diesel particulate filter) portion of the DECSE (Diesel Emission Control - Sulfur Effects) Phase 1 test program. The DECSE program is a joint government and industry program to study the impact of diesel fuel sulfur level on aftertreatment devices. A systematic investigation was conducted to study the effects of diesel fuel sulfur level on (1) the emissions performance and (2) the regeneration behavior of a continuously regenerating diesel particulate filter and a catalyzed diesel particulate filter. The tests were conducted on a Caterpillar 3126 engine with nominal fuel sulfur levels of 3 parts per million (ppm), 30 ppm, 150 ppm and 350 ppm.

Engine technology in passenger vehicles continues to evolve to meet consumer needs, improve fuel efficiency and reduce emissions. Likewise, engine oil classifications and performance requirements have evolved to meet the demands of the latest engine technology. This paper explores the degradation of engine oil quality in service by monitoring the condition of the used oil samples obtained from real-world, non-fleet consumer applications. In a previous study (SAE 2003-01-1957), used oil analysis results were reported for API/ILSAC GF-2 engine oil samples to determine oil degradation trends during service life. These samples were collected from a variety of vehicles, representing different driving conditions and oil brands. Each sample was analyzed to monitor additive depletion, accumulation of contaminants, and change in the physical and chemical properties of the oils. This study is a continuation of the previous work and includes API/ILSAC GF-4 engine oil samples.

The majority of passenger car and light-duty trucks, especially in North America, operate using port-fuel injection (PFI) engines. In PFI engines, the fuel is injected onto the intake valves and then pulled into the combustion chamber during the intake stroke. Components of the fuel are unstable in this environment and form deposits on the upstream face of the intake valve. These deposits have been found to affect a vehicle’s drivability, emissions and engine performance. Therefore, it is critical for the gasoline to be blended with additives containing detergents capable of removing the harmful intake valve deposits (IVDs). Established standards are available to measure the propensity of IVD formation, for example the ASTM D6201 engine test and ASTM D5500 vehicle test.

One possibility to improve the fuel economy of SI-engines is to run the engine with a lean air-fuel-ratio (AFR). Hydrocarbon and carbon monoxide after-treatment has been proven under lean operation, but NOx-control remains a challenge to catalyst and car manufacturers. One strategy that is being considered is to run the engine lean with occasional operation at stoichiometry. This would be in conjunction with a three-way-catalyst (TWC) to achieve stoichiometric conversion of the three main pollutants in the normal way and a NOx trap. The NOx trap stores NOx under lean operation to be released and reduced under rich conditions. The trap also functions as a TWC and has good HC and CO conversion at both lean and stoichiometric AFR's. Under lean conditions NO is oxidised to NO2 on Pt which is then adsorbed on an oxide surface. Typical adsorbent materials include oxides of potassium, calcium, zirconium, strontium, lanthanum, cerium and barium.

It is anticipated that worldwide energy demand will approximately double by 2050, whilst at the same time, CO2 emissions need to be halved. Therefore, there is increasing pressure to improve the efficiency of all machines, with great focus on improving the fuel efficiency of passenger cars. The use of downsized, boosted, gasoline engines, can lead to exceptional fuel economy, and on a well-to-wheels basis, can give similar CO2 emissions to electric vehicles (depending, of course, on how the electricity is generated). In this paper, the development of a low weight concept car is reported. The car is equipped with a three-cylinder 0.66 litre gasoline engine, and has achieved over 100 miles per imperial gallon, in real world driving conditions.

Two campaigns measuring on-road emissions of 23 VN-trucks on a randomly chosen driving cycle, consisting of 10 miles two-lane and 8 miles four-lane road were performed. The first, during October 2004, showed tailpipe NOx emissions on fleet average of 1.06 g/bhp-hr including the time the exhaust gas temperature was below 200°C. The second, during June 2005, showed tailpipe NOx emissions on fleet average of 1.13 g/bhp-hr including the time the exhaust gas temperature was below 200°C. Complementary measurements in a SET-cycle (13 point OICA-cycle) on a chassis dynamometer showed a tailpipe emission of 0.008 g PM per bhp-hr. Moreover, cost analysis show that the diesel fuel consumption remains unchanged whether the truck running on ULSD is equipped with a Combined Exhaust gas AfterTreatment System (CEATS) installed or not.

Six 2001 International Class 6 trucks participated in a project to determine the impact of gas-to-liquid (GTL) fuel and catalyzed diesel particle filters (DPFs) on emissions and operations from December 2003 through August 2004. The vehicles operated in Southern California and were nominally identical. Three vehicles operated “as-is” on California Air Resources Board (CARB) specification diesel fuel and no emission control devices. Three vehicles were retrofit with Johnson Matthey CCRT® (Catalyzed Continuously Regenerating Technology) filters and fueled with Shell GTL Fuel. Two rounds of emissions tests were conducted on a chassis dynamometer over the City Suburban Heavy Vehicle Route (CSHVR) and the New York City Bus (NYCB) cycle. The CARB-fueled vehicles served as the baseline, while the GTL-fueled vehicles were tested with and without the CCRT filters. Results from the first round of testing have been reported previously (see 2004-01-2959).

Due to the recent drive to reduce CO₂ emissions, the turbocharged direct injection spark ignition (turbo DISI) gasoline engine has become increasingly popular. In addition, future turbo DISI engines could incorporate a form of charge dilution (e.g., lean operation or external EGR) to further increase fuel efficiency. Thus, the conditions experienced by the fuel before and during combustion are and will continue to be different from those experienced in naturally aspirated SI engines. This work investigates the effects of fuel properties on a modern and prototype turbo DISI engine, with particular focus on the octane appetite: How relevant are RON and MON in predicting a fuel's anti-knock performance in these modern/future engines? It is found that fuels with high RON and low MON values perform the best, suggesting the current MON requirements in fuel specifications could actually be detrimental.

A fleet of six 2001 International Class 6 trucks operating in southern California was selected for an operability and emissions study using gas-to-liquid (GTL) fuel and catalyzed diesel particle filters (CDPF). Three vehicles were fueled with CARB specification diesel fuel and no emission control devices (current technology), and three vehicles were fueled with GTL fuel and retrofit with Johnson Matthey's CCRT™ diesel particulate filter. No engine modifications were made. Bench scale fuel-engine compatibility testing showed the GTL fuel had cold flow properties suitable for year-round use in southern California and was additized to meet current lubricity standards. Bench scale elastomer compatibility testing returned results similar to those of CARB specification diesel fuel. The GTL fuel met or exceeded ASTM D975 fuel properties. Researchers used a chassis dynamometer to test emissions over the City Suburban Heavy Vehicle Route (CSHVR) and New York City Bus (NYCB) cycles.

Recently, significantly more demanding emissions standards for the Mercosur region were proposed, and the intention is that these will be introduced in 2004 and 2008. This paper describes the development of new high performance three-way catalyst formulations for conventional gasoline/gasohol fueled engines that enables them to meet these stringent standards without increasing the content of platinum group metals above the levels currently employed. The performance benefits of these advanced platinum and palladium-based catalysts are demonstrated on both engine bench and vehicles.

The use of hydrocarbon traps to reduce cold-start emissions is one of the numerous methods that have been suggested to meet ULEV hydrocarbon emission requirements. To aid in our understanding of hydrocarbon traps and in the design of improved hydrocarbon trap systems, in-situ mass spectrometry has been used to speciate several hydrocarbons during the first 505 seconds of an FTP from the exhaust of a 2.0 L vehicle fitted with hydrocarbon traps in the after treatment system. This technique allows second-by-second engine-out and vehicle-out hydrocarbon speciation. The in-situ mass specrometry technique has shown that hydrocarbon traps are generally effective for trapping aromatics and C4+ alkanes and alkenes, but are ineffective in trapping methane, ethane, and ethene: Further improvements in the trapping performance for C3-C5 hydrocarbons can be made by placing a water trap in front of the hydrocarbon trap.

Injector nozzle deposits can have a profound effect on particulate emissions from vehicles fitted with Gasoline Direct Injection (GDI) engines. Several recent publications acknowledge the benefits of using Deposit Control Additives (DCA) to maintain or restore injector cleanliness and in turn minimise particulates, but others claim that high levels of DCA could have detrimental effects due to the direct contribution of DCA to particulates, that outweigh the benefits of injector cleanliness. Much of the aforementioned work was conducted in laboratory scenarios with model fuels. In this investigation a fleet of 7 used GDI vehicles were taken from the field to determine the net impact of DCAs on particulates in real-world scenarios. The vehicles tested comprised a range of vehicles from different manufacturers that were certified to Euro 5 and Euro 6 emissions standards.

Laminar burning velocity is a fundamental combustion property of any fuel/air mixture. Formulating gasoline fuel blends having faster burning velocities can be an effective strategy for enhancing engine and vehicle performance. Formulation of faster burning fuels by changing the fuel composition has been explored in this work leading to a clear correlation between engine performance and fuel burning velocity. In principle a gasoline vehicle should be calibrated to give optimal ignition timing (also known as MBT - minimum spark advance for best torque) while at the same time avoiding any possible engine knock. However, modern downsized/boosted engines frequently tend to be limited by knock and the spark timing is retarded in respect of the optimum. In such scenarios, faster burning fuels can lead to a more optimum combustion phasing resulting in a more efficient energy transfer and hence a faster acceleration and better performance.

Piston ring and liner wear measurements and analyses were performed in a production 3.6L V6 gasoline engine with radiolabelled engine parts. Three isotopes were generated: one in the engine liner using surface layer activation; one each in the top ring face and top ring side using bulk activation. Real-time wear measurements and subsequent rates of these three surfaces were captured using the radioactive decay of the isotopes into the engine oiling system. In addition, surface roughness and wear profile measurements were carried out using white light interferometry. The results from Phase I provided insights on evolution of wear and wear rates in critical engine components in a gasoline engine. Phase II will extend this work further and focus on evaluating the fuel additive effects on engine wear.