Abstract: A mobile computing device presents a set of user interface (UI) elements and receives user input corresponding to a set of vehicle specification values (e.g., engine type, transmission type, axle ratio) via the set of UI elements. The mobile computing device obtains (e.g., from a remote computer system hosted by a vehicle manufacturer) a vehicle performance value (e.g., a fuel economy value or a greenhouse gas emission value), an optimization value for the vehicle performance value, and vehicle specification analysis information based at least in part on the set of vehicle specification values. The mobile computing device presents the vehicle performance value, the optimization value, and vehicle specification feedback to a user. The vehicle specification feedback is based at least in part on the optimization value and the vehicle specification analysis information.