An important target for car manufacturerswhen developing new cars is to reduce fuelconsumption. One approach to this problem is to usea downsized turbocharged engine. To fully utilize thebenefits of the new hardware introduced, good controlsystems are needed. This paper presents a nonlinearcontroller for controlling the exhaust pressure in aSI engine equipped with VGT. A mapping from thestates, inputs and disturbances to future outputs isformed, and inverting the input-output relation inthis mapping gives a control law. An analysis showsthat the controller adapts its gain to the input-outputsensitivity. The controller is evaluated using both simulationsand measurements on a real engine, showingthe benefit of using the nonlinear controller over acorresponding linear controller.