This project presents a comprehensive preliminary design tool for the sizing of key subsystems in an electric vehicle, with a specific focus on urban driving applications. The tool integrates a genetic algorithm (GA) to optimize critical design parameters, including battery capacity (kWh), wheel diameter (inches) and a structural coefficient representing chassis material utilization. The objective of the GA is to minimize the simulated energy consumption (expressed in kWh) while ensuring that the overall vehicle mass (the sum of the subsystem masses, auxiliary systems, and a fixed extra mass) remains within a tight tolerance of the target mass. The tool employs detailed subsystem models to estimate both energy consumption and mass distribution.