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With the implementation of Euro V emissions legislation in 2010, the vast majority of light-duty diesel vehicles now employ a diesel particulate filter. The expansion of the Diesel Euro V standard outside Europe is inhibited in part by the low availability of ≺50 ppm sulfur fuel. Having said this, countries such as India and China have ≺50 ppm sulfur fuel available in many urban centers today, with the geographical area covered growing each year. Whilst it is well known that diesel DPF applications require ≺50 ppm sulfur fuel for optimum long-term operation, the ability of the system to withstand periodic "high" sulfur events would be a useful enabler for the early implementation of Euro V legislation to these markets. In this paper, the authors set out to assess the capability of the DOC and cDPF exhaust gas aftertreatment system to cope with periodic high sulfur fuel events.

Over the past several years, monolithic catalytic converters with laminar flow profile are being used by automotive industry. These catalytic converters, though create some turbulence at the inlet, make the majority of the rest of the flow laminar, thereby reducing the mass transfer of the exhaust components to the effective catalytic sites. Improvements were achieved only through the higher cell densities so far. If the design change in the substrates allows the change of exhaust flow from laminar to turbulent, longer residence time can be achieved and more unconverted gases from the core of the channel come closer to the catalyst surfaces facilitating more reaction with the active catalytic sites. The turbulent technology has been successfully developed more recently with metal substrates to get the required turbulent flow characteristics in the substrate channels.

This paper describes the process utilized in the design and development of a 75 cc powertrain for two wheeled vehicles. The powertrain was designed for the optimum combination of fuel efficiency, reliability, performance and low initial cost. A new approach to the design of these powertrains was utilized, which included the use of a high pressure die cast aluminum cylinder head with high tumble ports, a single piece crankshaft with cracked two piece connecting rod and plain bearings on crank and camshafts. The process of design and development made extensive use of new analytic and experimental methods, which are described in this paper.