A system and method for monitoring fuel efficiency of a vehicle is provided. Fuel efficiency of a vehicle may be monitored in real-time using telemetry transmitted from the vehicle. The telemetry may be analyzed in combination with a fuel efficiency model in order to determine whether the real-time fuel efficiency determination deviates from a baseline fuel efficiency. The real-time fuel efficiency monitoring system and method may be used for feedback for the driver, such as sending real-time messages to the driver to modify operation of the vehicle to increase fuel efficiency. The fuel efficiency model may further be used to assign vehicles in a fleet to particular routes, vehicles to particular drivers, or vehicles to particular routes with particular drivers.