This report identifies and describes the significant vehicle and engine design and operating parameters relevant to articulated vehicle fuel consumption and fuel usage for a given amount of useful work performed. An evaluation method has been proposed and developed and a data base established for use in systematic studies of the effect of gross vehicle weight on fuel consumption. A range of articulated vehicle options was proposed from 18 to 44 tonne gross weight. The parameters assigned to each vehicle option included: unladen weight, rated payload, effective vehicle mass, engine, accessory and transmission system characteristics, wind averaged drag and tyre rolling resistance. Test routes were selected and driving techniques specified for simulation purposes. An example of the application of the method of evaluation has been given. It has been assumed that the transient operating conditions of the vehicle can be simulated using steady state operating points from engine performance maps and measurements of resistive forces obtained under steady state vehicle operating conditions. Despite the fundamental limitations inherent in these assumptions, the simulation technique has proved to be a useful method of evaluating the relative fuel consumption of heavy articulated vehicles. (Author/publisher)
Abstract