V12s

V12s are internal combustion engines with twelve cylinders arranged in two banks of six that share a common crankshaft in a V configuration. The arrangement is typically used in high-performance and luxury cars, as well as in some aircraft and marine engines. Most V12s are water-cooled and can feature overhead camshafts and a long crankshaft, which influences engine bay packaging and weight.

Design and operation: The two banks form a V, commonly around 60 degrees, to balance primary forces and minimize vibration. The cylinders fire in a sequence that aims for smooth, near-continuous power delivery. The engine’s length and torque curve contribute to refined feel at highway speeds and strong high-end performance, albeit at greater mechanical complexity and mass than many other layouts.

Characteristics and trade-offs: Advantages include exceptional smoothness, broad and linear torque, and high-revving potential in performance variants. Disadvantages involve greater size, weight, cost, and maintenance complexity, as well as packaging constraints in smaller vehicles and typically higher fuel consumption compared with smaller, more modern powertrains.

Applications: V12s have been used in luxury and performance automobiles, aircraft engines of the early to mid-20th century, and some marine applications. They are favored where refinement, power, and high-speed response are valued, despite efficiency and packaging penalties.

Notable engines: The Ferrari Colombo V12 and the later Ferrari F140 V12 family are prominent in automotive history. The Rolls-Royce Merlin V12 is a well-known WWII-era aircraft engine. The Mercedes-Benz M120 V12 represents a late-20th-century automotive implementation of the layout.