Predicting the effect of powertrain preconditioning on vehicle efficiency

Under extreme climatic conditions, the vehicle fuel consumption can be far from the certified value. Given the growing concern for polluting emissions, it is necessary to investigate a way to improve the overall vehicle efficiency and thus reduce the emissions and fuel consumption gap. One solution is to pre-warm the gearbox and the engine in order to make it work at an optimal temperature to achieve the best efficiency possible. Indeed, low lubricant temperature is a source of reduced vehicle efficiency due to the lubricant viscosity rising exponentially at very low temperature. Using the Powertrain Dynamics library, a vehicle model with a detailed equation-based gearbox model taking into account the temperature-dependent losses and a map-based engine including temperature-dependent emission models (CO, NOx, HC and particulates) is developed.