An automotive vehicle includes an internal combustion engine and an exhaust system. The exhaust treatment system includes a dosing system that injects NH3 into an exhaust gas stream generated by the engine. An SCR device stores an amount of the NH3 and converts NOx into diatomic nitrogen (N2) and water (H2O) based on the stored amount of the NH3. The vehicle further includes an SCR status estimator device and a controller. The SCR status estimator device determines an NH3 coverage ratio (R), which indicates a stored amount of NH3 with respect to a maximum NH3 storage capacity of the SCR device. The controller determines a target NOx reduction efficiency (ηNOx) of the SCR device, and an NH3 coverage ratio set point (Rsp) based on the ηNOx. The controller also generates an NH3 control signal (u) that controls the dosing system based on a comparison between the R and the Rsp.