FUEL ECONOMY IN PEAK HOUR TRAVEL

The significance of urban road vehicles as the largest user of liquid transport fuel is pointed out. In an investigation aimed at assessing the fuel used against inertia forces (which together with rolling resistance form the most important components of energy usage in urban driving), fuel consumption and speed/time data have been obtained for a passenger vehicle travelling over a variety of routes in urban Melbourne. Fuel consumption has been related to an acceleration index (derived from the speed/time trace) which represents the acceleration conditions experienced by the vehicle. This index is proposed as a basis for a road fuel consumption test under "floating car" conditions and for determining aggregate fuel consumption on a section of arterial road. The acceleration conditions experienced by the test car were found to differ from those which would occur in the saa draft standard city cycle for petrol consumption (i.e. That prescribed by adr.27a for emissions) and these differences are illustrated. /TRRL/