Lamborghini V12 discontinued their first-generation V12 after the Murcielago, opting for a brand-new V12 that first saw use on the Lamborghini Aventador. When Ferruccio Lamborghini set out to compete with Ferrari, he contracted Giotto Bizzarrini to design the engine for his car and, according to some accounts, paid him a bonus for every horsepower over what Ferrari's V12 could produce. The finished V12, with minor improvements, went on to become the 6.5 litre powering the Lamborghini Murciélago LP 640, and completed its service for Lamborghini with the final version of the Murciélago, the Murciélago LP 670-4 SuperVeloce. The engine was designed from
V12 engine the advantages of lower centers of gravity and improved pilot visibility for single-engined designs. Only the pre-war origin BMW VI V12 of Germany was an "upright" engine. The United States had the experimental Continental IV-1430 inverted V12 engine under development, with a higher power-to-weight ratio than any of the initial versions of the German WW II inverted V12s, but was never developed to production status, with only 23 examples of the Continental inverted V12 ever being built. The only American-design inverted V12 engine of any type to see even limited service in World War II was the air-cooled Ranger V-770,