  The paper discusses multistep nonlinear model-predictive control (NMPC)
schemes for the tracking of a car model along a given reference track. In
particular we will compare the numerical performance and robustness of classic
single step NMPC, multistep NMPC without re-optimization, multistep NMPC with
re-optimization, and multistep NMPC with sensitivity updates instead of a full
re-optimization.
