European transient cycle

ESC European Steady Cycle, ETC European Transient Cycle ... 

ETC European transient driving cycle (for heavy-duty vehicles)... 

Likewise, Fig. 112 shows the conversion efficiency for diesel particulate matter reached in the US transient cycle with a diesel catalyst mounted on a heavy duty engine. Table 29 shows the conversion for CO, HC and particulate matter in the European 13-mode test performed with a heavy duty engine for a fresh and for an engine-aged catalyst. The catalyst performance at operating conditions, reflecting the lowest and the highest exhaust gas temperature in this 13-mode test, is also reported. 

Table lEuropean Diesel Passenger Car Emissions Standards (European Transient Test Cycle)... 

A variety of catalyst substrates, washcoats, and formulations were screened on a Mercedes OM 366 LA direct injection, turbocharged-intercooled engine in order to identify the optimal engine/catalyst combination for US applications. The engine was operated at five steady state modes, and on the US transient and European 13-mode cycles. 

Rather than work to achieve a simplified duty cycle and simplified umbrella transients, more exacting and realistic analyses could be performed. The currently available computing power allows these multiple analyses to be performed, facilitating optimization and removing the necessity for very conservative approaches to be taken to minimize and simplify calculations and analyses. At the same time the actual safety margins can be much better understood and more transparent, thus resolving one of the past difficulties between US and European design requirements. 

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