may incorporate a diesel engine or a model of the engine a selective catalytic reduction exhaust after treatment mechanism for connection to the engine an engine controller and a selective catalytic reduction controller connected to the selective catalytic reduction exhaust after treatment mechanism and to the engine controller the engine controller and the selective catalytic reduction controller may provide coordinated control of the engine and selective catalytic reduction selective catalytic reduction exhaust after treatment mechanism to control an amount of pollutants in an exhaust emission from the engine the items noted herein may be modeled the engine controller and the selective catalytic reduction controller may provide coordinated control of the engine and selective catalytic reduction exhaust after treatment mechanism to optimize selective catalytic reduction of pollutants in the exhaust emission so as to reduce specific fuel consumption and or particulate matter emission the engine controller and the selective catalytic reduction controller may be model predictive controllers the selective catalytic reduction exhaust after treatment mechanism may provide a catalyst into the exhaust emission for selective catalytic reduction of the pollutants in the exhaust emission the pollutants may have nox the selective catalytic reduction may incorporate reducing nox in the exhaust emission an amount of urea.