In order to approach the Carnot efficiency in modern diesel engines that see variable loads and high speeds, programmable electrically controlled fuel injections are required. Traditional solenoid based transducers are binary and cannot achieve this programmability while newer piezoelectric transducers are susceptible to performance degradation due to high pressures and temperatures. This paper presents the experimental characterization of a programmable diesel fuel injector transducer designed by Great Plains Diesel Technologies, L.C. to address the limitations of existing technology. This transducer employs a little-known magnetostrictive alloy to position its needle. In contrast to piezoelectric ceramics, quantum mechanics endows this alloy with the indestructible property of magnetostriction, the ability to strain proportional to a magnetic field. This allows it to be fast and infinitely adjustable (or, “programmable”) without degradation.