Abstract

The apparatus gives a simultaneous readout of the semi-instantaneous rate of fuel consumption, expressed in terms of miles per gallon; the distance traveled; and the total amount of gallons consumed since the apparatus was last reset for a moving vehicle powered by an internal combustion engine. The fuel is metered by a flow transducer which emits a pulse rate representative of fuel flow rate while at the same time the miles traveled by the moving vehicle are measured by a distance transducer also emitting a pulse rate. Both pulse rates are fed to digital integrated circuitry that provides readouts for miles traveled, total fuel consumed and for the semi-instantaneous miles per gallon.The apparatus also includes a reset switch, a hold switch to maintain the indicator readings while not inhibiting the accumulation of further counts, and internal switches to accommodate vehicle-to-vehicle variations in rear end ratios and tire sizes.The method comprises the steps of generating a first series of pulses related to fuel flow to the engine so that a predetermined amount of fuel is consumed by the engine prior to emission of a pulse; generating a second series of pulses related to the distance traveled by the vehicle; summing and displaying a sum of all of the second-series pulses accumulated before a pulse emission from the first series. This displayed sum is then replaced by a subsequent sum accumulated up to emission of a respective subsequent pulse from the first series.Other steps include summing and displaying the entire first and second pulse series to respectively represent total fuel consumed and total miles traveled.