The present invention encompasses a system and method for automatically replacing vehicle fluid, such as engine oil, with a robotic serving unit or robotic machine. The robotic machine comprises a motorized, autonomously maneuverable unit that has on its top a drainage arm to connect with an oil drain plug of a vehicle. In a preferred embodiment, the oil drain plug comprises a hollow interior for the drainage arm to connect with and drain the oil, and can also comprise a sealable element to retain the oil.