Abstract: Apparatus for measuring fuel consumption in an internal combustion engine having controllable fuel injectors that meter fuel to corresponding cylinders at predetermined delivery rates under throttle control senses the amount of fuel being delivered to each cylinder by a potentiometer that generates a signal which is proportional to the linear displacement of a throttle rack gear. In one embodiment a transducer generates another signal proportional to the rotary speed of the engine and both signals are amplified at a fixed gain corresponding to the number of working engine cylinders to produce a product signal that is applied to an analog meter or a digital display circuit which indicate the rate of engine fuel consumption.