The ESX II was dubbed a "mybrid" (mild hybrid) because its reliance on electrical power was not highly dependent on the battery. This system contained two motors that worked in parallel: a 1.5 L 74 bhp direct-injection diesel and a 20 bhp AC-induction electric motor. Coupled with the powertrains were a 5-speed electronically shifted manual transmission, a nickel-metal hydride battery pack, and controlling equipment which included components from the Patriot hybrid race-car program. The main power came from the diesel engine. The electric motor charged the batteries, added to the acceleration, and powered the reverse gear.