V12 Engine - V12 Road Cars

V12 Road Cars

In automobiles, V12 engines have not been common due to their complexity and cost. They are used almost exclusively in expensive sports cars and luxury cars because of their power, smoother operation, and distinctive sound.

Prior to World War II, 12-cylinder engines were found in many luxury models, including cars from: Packard 1916 to 1923, Daimler 1926 to 1937, Hispano-Suiza 1931, Cadillac 1931, Auburn 1932, Franklin 1932, Lincoln 1932, Rolls-Royce 1936, and Pierce-Arrow also 1936.

Until the general adoption of vibration isolating engine mounts in the 1930s, vehicles with 8-, 12-, and 16-cylinders provided higher levels of refinement.

Packard's 1916 "Twin Six" is widely regarded as the first production V12 engine. With a list price of US$1,000, the Auburn was the lowest priced V12 car ever (unadjusted for inflation). Production cost savings were achieved by using horizontal valves, which did not make for an efficient and powerful combustion chamber. Between 1916 and 1921, there was a vogue of V12s, during which National (Indianapolis) copied the Packard engine, and Weidely Motors (also of Indianapolis) offered a proprietary engine. Soon after the end of World War I, Lancia offered a 22° V12, Fiat had a 60° model 520 (1921-2), British truck manufacturer Ensign announced a V12 that did not materialize, and in 1926, Daimler (Britain) offered the first of a full range of sleeve valve Double Sixes, 7,136 cc, 3,744 cc, 5,296 cc and 6,511 cc versions remaining available until 1937. In 1927 more entered the market from, Cadillac, Franklin, Hispano-Suiza, Horch, Lagonda, Maybach, Packard, Rolls, Tatra, Voisin, and Walter offering V12 engines. Cadillac (from 1930 to 1940) and Marmon (1931–1933) even developed V16 engines.

Improvements in combustion chamber design and piston form enabled lighter V8 engines to surpass the V12 in power starting from the 1930s; only the smaller, H-Series Lincoln V-12 remained after WWII and it was replaced by a V8 in 1949. Similarly, as they seemed excessive for the postwar market in Europe, production of V12-engined-cars was very limited until the 1960s.

Ferrari has traditionally reserved their top V12 engine for their top-of-the line luxury sports coupes since 1949. Ferrari's closest rival, Lamborghini has also used the V12 configuration for many of its road cars since the company's inception in 1963. In 1972, Jaguar came out with the XJ12, equipped with a 5.3 litre V12, which continued (after revisions in 1993) until the 1996 model year, after which the marque discontinued the twelve-cylinder engine.

German manufacturer BMW returned to V12 designs for its 7-Series sedan in model year 1986, forcing Mercedes-Benz to follow suit in 1991. While BMW sells far fewer V12-engined 7-Series vehicles than V8 versions, the V12 retains popularity in the US, China, and Russia, as well as maintaining the marque's prestige in the luxury vehicle market segment. The BMW-designed V12 also appears in Rolls-Royce cars, while the Mercedes engine is also seen in Maybach cars. In their full-sized sedans sold in Canada and the USA, Mercedes and BMW have mid-displacement V8s for the entry-level trims, while having the V12 as the flagship vehicle of the brand. For their most expensive Mercedes-Benz nameplates (S-Class, CL-Class, and SL-Class), there are V8-engined AMG models (55, 63) that have comparable power to their V12-powered cars (600).

In 1997, Toyota equipped their Century Limousine with a 5.0 L DOHC V12 (model # 1GZ-FE), making it the first and only Japanese production passenger car so equipped.

TVR made and tested a 7.7 L V12 called the Speed Twelve, but the project was scrapped after the car it was designed for was deemed too powerful for practical use. The only British marques currently using a V12 configuration are Aston Martin — whose Cosworth-developed engine was authorized during the company's ownership by Ford Motor Company — and Rolls-Royce.

In 2009, China FAW Group Corporation equipped their Hongqi HQE with a 6.0 L DOHC V12 (model # CA12VG), making it the first and only Chinese production passenger car so equipped.

Most production V12 engines in road cars have an even firing order, with the uneven-firing exceptions such as Aston Martin 5.9L V12 and Mercedes-Benz M275 AMG V12s.

In 2008 Audi launched their Q7 model with a 5.9-litre V12 twin-turbo diesel engine, making it the first production passenger car so equipped. The engine also appeared in the R8 V12 TDI concept car.