This paper builds a model to estimate current car fleet energy consumption in Andorra and forecasts such consumption as a reference scenario. It shows how a useful modelling tool can be developed and applied in the absence of significant data. The base-year model is built through a bottom-up methodology using vehicle registration and technical inspection data. The model forecasts energy consumption up to 2050, taking into account the fleet structure, the car survival profile, trends in activity of the various car categories, and the fuel price and income elasticities that affect car stock and total fleet activity. It provides an initial estimate of private car energy demand in Andorra and charts a baseline scenario that describes a hypothetical future based on historical trends. A local sensitivity analysis is conducted to determine the most sensitive input parameters and study the effect of its variability. In addition, four scenarios are built to represent the largest expected variability in the results with respect to the reference scenario and provide a broad estimate of potential energy savings related to different policy strategies