Ricardo have developed a systematic approach for the design of transient engine control strategies using advanced control techniques. The methodology was initially applied to the design of a testbed speed and torque controller. This enabled complex transient tests to be carried out with equipment normally used for steady-state testing. The same techniques were applied to the design of a controller for a variable geometry turbocharger aimed at vehicle applications. The influence of different control strategies on emissions and fuel economy was evaluated on a heavy-duty diesel engine over a section of the US FTP cycle. Particulate reductions of up to 34% were achieved without increasing NOx.