In this paper, the direct data-driven design method introduced in [6] is applied to the airpath control problem in turbocharged Diesel engines. The method allows the employed fixed-order multivariable controller to be tuned without need of mathematically describing the system, thus avoiding the problem of dynamic undermodeling. Experimental results on a testbench facility and comparison with an existing decoupled technique validate the suitability of the proposed method for the engine application. Moreover, suited instrumental variables show to be effective when dealing with real experimental noise. © 2012 AACC American Automatic Control Council).