Editing V12 engine (section)

=== 1920s to 1940s ===
[[File:1931Cadillac370AcoupeV12-engine.jpg|thumb|right |1931 [[Cadillac V-12#Series 370 (1931–1935)|Cadillac Series 370A]] engine]]

During the late 1920s, the number of marques offering V12 engines for their passenger cars increased and peaked in the 1930s. The lack of vibration and sound, inherent smoothness, and increased power were cited as key benefits for V12 engines.<ref>{{cite book |last=Georgano |first=G.N. |author-link=G.N. Georgano |title=Cars: Early and Vintage, 1886–1930 |publisher=Mason Crest |year=2002 |isbn=978-1-59084-491-5 |page=Chapter 3: Painless Sophistication |url-access=registration |url= https://archive.org/details/worldofwheels0000unse }}</ref> Automobile petrol produced in the 1920s and 1930s had lower [[octane rating]], leading to lower engine performance ratings, and [[Bushing (isolator)#History|vibration isolating engine mounts]] were rarely fitted to the passenger cars in the 1920s and the early 1930s. Adding more cylinders to the engine was one of several techniques for performance increase.

European passenger cars with V12 engines were:
*[[Fiat 520|Fiat 520 'Superfiat']] (1921–1922)
*[[Daimler Double-Six sleeve-valve V12|Daimler Double-Six]] (several models built at different times from 1926 to 1938)
*{{ill|Horch 12|de|vertical-align=sup}} (1931–1934)
*[[Hispano-Suiza J12]] (1931–1938)
*[[Maybach Zeppelin]] DS 7 (1928–1930) and DS 8 (1930–1938)
*[[Rolls-Royce Phantom III]] (1936–1939)
*[[Tatra 80]] (1931–1935)

American passenger cars with V12 engines were:
*[[Auburn Automobile|Auburn V-12 Speedster]] (1932–1934)<ref>{{cite web |title=1932 Auburn V-12 Speedster |url= https://rmsothebys.com/en/auctions/AZ12/Arizona/lots/r241-1932-auburn-v-12-speedster/280418 |website=rmsothebys.com |access-date=21 February 2020 |language=en |date=21 July 2017}}</ref>
*[[Cadillac V-12]] (1931–1937) 
*[[Franklin (automobile)|Franklin V-12]] (1932–1934)<ref>{{cite web |title=1932–1934 Franklin V-12 |url=https://auto.howstuffworks.com/1932-1934-Franklin-v12.htm |website=howstuffworks.com |access-date=21 February 2020 |language=en |date=24 October 2007 |archive-date=21 February 2020 |archive-url=https://web.archive.org/web/20200221103350/https://auto.howstuffworks.com/1932-1934-Franklin-v12.htm |url-status=dead }}</ref>
*[[Lincoln K series|Lincoln K-series/Model K]] (1931–1940)
** [[Lincoln Custom|Custom]] (1941–1942)
** [[Lincoln Continental#First generation (1940–1942, 1946–1948)|Continental]] (1940–1948)
*[[Lincoln-Zephyr|Lincoln-Zephyr V-12]] (1936–1942)
** [[Lincoln-Zephyr#H-series|H-series]] (1946–1948)
*[[Packard Twelve|Packard Twin Six]] (1916–1923 and 1932)
** Packard 905 (1916–1923)
** [[Packard Twelve]] (1933–1939)
*[[Pierce-Arrow|Pierce-Arrow Twelve]] (1932–1938)<ref>{{cite web |url=https://auto.howstuffworks.com/1932-1938-pierce-arrow-twelve.htm |title=1932–1938 Pierce-Arrow Twelve |website=howstuffworks.com |access-date=2 September 2020 |archive-date=25 September 2020 |archive-url=https://web.archive.org/web/20200925143514/https://auto.howstuffworks.com/1932-1938-pierce-arrow-twelve.htm |url-status=dead }}</ref>
** [[Pierce Silver Arrow]] (1933)

Economic hardships caused by the [[Great Depression]] meant that all American automakers except for Lincoln had discontinued production of V12 engines by the end of the 1930s. Lincoln themselves would cease V12 production in 1948, and no American automaker has built V12 engines since. Improvements in engine design, namely combustion chamber, piston form, fuel delivery system, and such enabled the lighter and cheaper V8 engines to surpass V12 engines in performance.

{{clear right}}