A system for reclaiming fuel from a vehicle fleet is comprised of a trailer capable of defueling multiple vehicles simultaneously that operates in conjunction with a remote computing device. The remote computing device communicates bi-directionally with an on-board computing device located in a combustion engine vehicle, where the on-board computing device is directed by the remote computing device to cause the vehicle's fuel pump to operate without starting the vehicle's engine. The remote computing device also queries for and receives data about the vehicle from the on-board computing device, such as the Vehicle Identification Number, diagnostic information about the vehicle, and/or data about how the vehicle is being driven and transmits such data to at least one second computing device in communication with the remote computing device.