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This work compared the piston deposit ratings in an engine when it was run on gasoline with a high concentration of deposit control additive (DCA) versus gasoline with a low concentration of additive. The additives came from different sources and contained detergents with different functional groups. The engine was a Ford V-8 PFI engine, which is used in ASTM D6593, the Sequence VG test. The experimental procedure followed the ASTM protocol, except for the fuel, which was treated with additives. Deposit ratings were better, at 95% confidence, in the tests using a high concentration of additive versus the tests using a low concentration.

It is expected that the world's energy demand will double by 2050, which requires energy-efficient technologies to be readily available. With the increasing number of vehicles on our roads the demand for energy is increasing rapidly, and with this there is an associated increase in CO₂ emissions. Through the careful use of optimized lubricants it is possible to significantly reduce vehicle fuel consumption and hence CO₂. This paper evaluates the effects on fuel economy of high quality, low viscosity heavy-duty diesel engine type lubricants against mainstream type products for all elements of the vehicle driveline. Testing was performed on Shell's driveline test facility for the evaluation of fuel consumption effects due to engine, gearbox and axle oils and the variation with engine operating conditions.

A predictive model for estimating the fuel saving of “top tier” engine, axle and transmission lubricants (compared to “mainstream” lubricants), in a heavy duty truck, operating on a realistic driving cycle, is described. Simulations have been performed for different truck weights (10, 20 and 40 tonnes) and it was found that the model predicts percentage fuel economy benefits that are of a similar magnitude to those measured in well controlled field trials1. The model predicts the percentage fuel saving from the engine oil should decrease as the vehicle load increases (which is in agreement with field trial results). The percentage fuel saving from the axle and gearbox oils initially decreases with load and then stays more or less constant. This behaviour is due to the detailed way in which axle and gearbox efficiency varies with speed/load and lubricant type.

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.

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.

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.

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).

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.

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.

Particulate mass (PM) emissions from DISI engines can be reduced via fuels additive technology that facilitates injector deposit clean-up. A significant drawback of DISI engines is that they can have higher particulate matter emissions than PFI gasoline engines. Soot formation in general is dependent on the air-fuel ratio, combustion chamber temperature and the chemical structure and thermo-physical properties of the fuel. In this regard, PM emissions and DISI injector deposit clean-up were studied in three identical high sales-volume vehicles. The tests compared the effects of a fuel (Fuel A) containing a market generic additive at lowest additive concentration (LAC) against a fuel formulated with a novel additive technology (Fuel B). The fuels compared had an anti-knock index value of 87 containing up to 10% ethanol. The vehicles were run on Fuel A for 20,000 miles followed by 5,000 miles on Fuel B using a chassis dynamometer.

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.

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.