Abstract: Precision gauge for liquid fuel in a vehicle's tank, based on the usage of electronic scales, a computer, the odometer and an electronic circuit based on the tank weight previous to the loading (Weight 1), density of the used fuel (previously digitized in the computer) and the weight of the tank after loading it (Weight 2); allows visualizing by means of a proper device (digital display), the volume of fuel contained in such tank, VOLUME_=(Weight 2?Weight 1)/DENSITY and eventually to appreciate the amount of fuel consumed by the vehicle per unit of time and/or per kilometer covered.