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The internal combustion engine and associated powertrain are likely to remain the mainstay of mobility over the next twenty years and to remain a significant portion of the portfolio of technologies employed over a much longer period of time. Efficient combustion of all fuels (petroleum based or alternative) requires copious amounts of air particularly with downsized engines. Turbocharging technology thus becomes an even more critical part of reducing both global warming gas and urban pollutant emissions from IC engines. Gasoline engine downsizing and turbocharging have been shown to improve fuel economy by ∼20% in production vehicles. In addition to data over a wide range of engines/vehicles, the results of a simple analysis done on vehicles/engines/drive cycles are presented to show the benefits of turbocharging and downsizing in a parametric variation of downsizing in combination with other technologies.

Diesel engines face increasingly stringent emissions regulations worldwide. The trade-off between fuel economy and NOx emissions and between NOx and particulate emissions is becoming more critical. In light of these regulations and design trade-offs among many variables, engine-boosting systems have become increasingly important. An advanced variable nozzle turbocharger (AVNT™) is described. The innovative design is described along with key characteristics. The design features a minimization of additional parts associated with the variable geometry mechanism and electro-hydraulic actuation integrated with the bearing system. The impact of variable geometry turbocharging on diesel engine performance, fuel economy, torque, emissions and braking capability is described. It is shown that significant improvements in all five variables are readily possible with the use of this variable geometry turbocharger.