PM—Power and Machinery: Effects of Engine Control Strategies and Transmission Characteristics on the Exhaust Gas Emissions from an Agricultural Tractor

Fuel consumption and emissions of a specific tractor engine depend mainly on engine speed and torque. The engine load can be influenced by alternative driving techniques, by the design of the drive train and by use of implements with different work capacities. This work deals with the effects of varying engine control strategies and engine transmission characteristics on the fuel consumption and engine emissions from agricultural tractors. The study employed a dynamic computer model of the tractor and the loading implement, on which simulation experiments could be conducted. The simulated operations were on-road transport and soil cultivation. A general conclusion of the work was that, by using varying driving strategies and transmission characteristics, it is possible to affect the amount of emissions to a considerable extent without affecting the time or fuel consumption for the operation. A more specific conclusion was that a decreased final gear ratio reduced the emission of hydrocarbons (HC) and CO, but increased the amount of nitrogen oxides (NOX) for the transport operation, while the emissions from the soil cultivation operation were only marginally affected. A further conclusion was that the maximum transport velocity influenced fuel consumption and emissions in relation to distance travelled to a modest extent only.