OPPORTUNITIES TO REDUCE FUEL CONSUMPTION OF A DUTY VEHICLE

Presently, environmental protection and ecology generally have become very important political subjects, for industrialized countries as well as at the international level. Atmospheric pollution is mainly due to road traffic downtown. To assess fuel consumption for duty vehicles we combine engine consumption maps with engine operating conditions as calculated by a vehicle simulation model. The model takes into account the vehicle characteristics (engine, transmission, etc.), including load, and characteristics of the route taken (road gradients and curves, speed limits, stops). This model calculates instantaneous operating conditions, in particular, the engine torque and speed, which in turn enables the calculation of fuel consumption. The fuel consumption was calculated for a small 3.5 ton duty vehicle. Simulated operating conditions correspond to highway, main road, and steady vehicle speeds for various values of road gradient, vehicle mass, rolling coefficient, aerodynamic coefficient; physically and empirically based methods are usually considered in modelling fuel consumption and emissions. The model uses vehicle parameters and second-by-second driving traces as inputs, and estimates second-by-second fuel consumption rates. This contribution deals with the possibilities of improving fuel consumption with constrictive measures pertaining to the vehicle, to the engine, and the gearing. These modifications are explained and listed. It has, however, become clear that the same performance at a reduced fuel consumption will only be realized in traffic if the driver acts accordingly and if the roads are suitably constructed.