This manuscript addresses the problem of employing well established model-based PID tuning formulæ, when only a nonparametric model of the process is available. The proposed solution expands the application possibility of such formulæ, and allows to set up autotuning procedures that join the simplicity of model-based formulæ with the power and accuracy of nonparametric modeling. Simulation and experiments are reported to motivate the proposed approach, and show its potential.