Editing Citroën (section)

===Traction Avant and Michelin ownership===
====Traction Avant====
The [[Citroën Traction Avant|Traction Avant]] is a car that pioneered the mass production of three revolutionary features that are still in use today: [[unibody|a unitary body with no separate frame]], four wheel [[independent suspension]] and [[front-wheel drive]]. Whereas for many decades, the vast majority of motor cars were similar in conception to the [[Ford Model T]] – a body bolted onto a [[Vehicle frame|ladder frame]] which held all the mechanical elements of the car, a [[Suspension (vehicle)#Suspension geometry|solid rear axle]] that rigidly connected the rear wheels and [[rear wheel drive]]. The ''Model T school'' of automobile engineering proved popular because it was considered cheap to build, although it did pose dynamic defects as automobiles were becoming more capable, and resulted in heavier cars, which is why today cars are more like the Traction Avant than the Model T under the skin.
In 1934 Citroën commissioned the American [[Budd Company]] to create a prototype, which evolved into the 7 fiscal horsepower (CV), {{cvt|32|hp-metric|kW|0}} Traction Avant.

{{multiple image
|align     = center
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|image1    = Citroën Traction Avant convertible.JPG
|width1    = 155
|caption1  = Pre-war [[Citroën Traction Avant]] Cabriolet
|image2    = Citroen B11 Sport 4-Door Berline 1951.jpg
|width2    = 260
|caption2  = [[Citroën Traction Avant]]
|image3    = Citroën Traction Avant Légère rear.JPG
|width3    = 225
|caption3  = [[Citroën Traction Avant]] Légère rear view
|image4    = 1956 Citroen Traction Avant - blue - svr (4637749504).jpg
|width4    = 180
|caption4  = 1956 [[Citroën Traction Avant]]
}}
Achieving quick development of the Traction Avant, tearing down and rebuilding the factory (in five months) and the extensive marketing efforts, were investments that resulted too costly for Citroën to do all at once, causing the financial ruin of the company. In December 1934, despite the assistance of the Michelin company, Citroën filed for bankruptcy. Within the month, [[Michelin]], already the car manufacturer's largest creditor, became its principal shareholder.<ref>{{cite web| url = http://www.uniquecarsandparts.com.au/heritage_citroen.htm| url-status = dead| archive-url = https://web.archive.org/web/20100823084352/http://www.uniquecarsandparts.com.au/heritage_citroen.htm| archive-date = 23 August 2010| title = Citroën Heritage}}</ref> However, the technologically advanced [[Citroën Traction Avant|Traction Avant]] had met with market acceptance, and the basic philosophy of cutting-edge technology used as a differentiator, continued until the late 1990s. [[Pierre Michelin (businessman)|Pierre Michelin]] became the chairman of Citroën early in 1935. [[Pierre-Jules Boulanger]], his deputy, became the vice-president and chief of the engineering and design departments. In 1935, the founder [[André Citroën]] died from stomach cancer.<ref>{{Cite book|url=https://archive.org/details/culturallifeofau0000giuc|url-access=registration|page=[https://archive.org/details/culturallifeofau0000giuc/page/61 61]|quote=stomach .|title=The Cultural Life of the Automobile: Roads to Modernity|last=Giucci|first=Guillermo|date=1 August 2012|publisher=University of Texas Press|isbn=9780292737846|language=en}}</ref>

====Research breakthroughs====
[[File:Meursault - Exposition véhicules militaires - 005.jpg|thumb|250px|Mid 20th century Citroën military truck]]
[[Pierre-Jules Boulanger]] had been a First World War air reconnaissance photography specialist with the [[French Air Force]]; he was capable and efficient and finished the war with the rank of captain. He was also courageous, having been decorated with the Military Cross and the Legion of Honour. He started working for [[Michelin]] in 1918, reporting directly to [[Édouard Michelin (born 1859)|Édouard Michelin]], co-director and founder of the business. Boulanger joined the Michelin board in 1922 and became president of Citroën in January 1938 after the death in a road accident of his friend [[Pierre Michelin (businessman)|Pierre Michelin]]<ref name=Automobilia1938>{{cite journal| title =Automobilia| journal = Toutes les Voitures Françaises 1938 (Salon [Oct] 1937)| volume = 6| page =26|year = 1998|publisher=Histoire & collections|location=Paris }}</ref> remaining in this position until his own death in 1950. In 1938, he also had become Michelin's joint managing director.<ref>{{Cite book|url=https://books.google.com/books?id=rTkACwAAQBAJ&q=pierre+jules+Boulanger+michelin+joint+managing+director+in+1938&pg=PA231|title=The Rise of the Global Company: Multinationals and the Making of the Modern World|last=Fitzgerald|first=Robert|date=7 January 2016|publisher=Cambridge University Press|isbn=9780521849746|language=en}}</ref>

During the [[German occupation of France in World War II]] Boulanger refused to meet Dr. [[Ferdinand Porsche]] or communicate with the German authorities except through intermediaries. He organized a "go slow" on production of trucks for the [[Wehrmacht]], many of which were sabotaged at the factory by putting the notch on the oil dipstick in the wrong place, which resulted in engine seizure. In 1944 when the [[Gestapo]] headquarters in Paris was sacked by the [[French Resistance]], his name was prominent on a [[Nazi]] blacklist of the most important enemies of the Reich, to be arrested in the event of an allied invasion of France.<ref>{{cite book|first=John | last = Reynolds|title=Citroën 2CV|isbn=978-1-84425-207-7|year=2005| publisher = Haynes Publishing PLC}}</ref>

Citroën researchers, including [[Paul Magès]], continued their work in secret, against the express orders of the Germans, and developed the concepts that were later brought to market in three remarkable vehicles – a small car (2CV), a delivery van (Type H) and a large, swift family car (DS). These were widely regarded by contemporary [[journalists]] as [[avant garde]], even radical, solutions to automotive design.
Thus began a decades-long period of unusual [[brand loyalty]], normally seen in the automobile industry only in niche brands, like [[Porsche]] and [[Ferrari]].

====2CV====
Citroën unveiled the [[Citroën 2CV]] or ''Deux Chevaux'' signifying two [[tax horsepower]] and initially only {{cvt|9|hp-metric|kW|1}}, at the [[Paris Salon]] in 1948. The car became a bestseller, achieving the designer's aim of providing rural [[French people]] with a motorized alternative to the [[horse]]. It was unusually inexpensive to purchase and, with its small two cylinder engine, inexpensive to run as well. The 2CV pioneered a very soft, interconnected suspension, but did not have the more complex [[Self-levelling suspension|self-levelling feature]]. This car remained in production, with only minor changes, until 1990 and was a common sight on French roads until recently; 9 million 2CV variants were produced in the period 1948–1990.<ref>John Reynolds. Citroën 2CV. {{ISBN|978-1-84425-207-7}}</ref>

{{multiple image
| align     = center
| direction = horizontal
| image1    = 1955 Citroen 2CV.jpg
| width1    = 200
| caption1  = [[Citroën 2CV|1955 Citroën 2CV]]
| image2    = Citroen 2CV Mezzana.jpg
| width2    = 200
| caption2  = [[Citroën 2CV|1989 Citroën 2CV]], with "Charleston" colours & shapes
| image3    = The Wondering Wine Company van (JHU 92N), 8 June 2013.jpg
| width3    = 225
| caption3  = [[Citroën H Van|Citroën type H / HY van]]
| image4    = Amboise 11.JPG
| width4    = 200
| caption4  = [[Citroën Ami]]
}}

====DS====
1955 saw the introduction of the [[Citroën DS|DS]], the first full usage of Citroën's [[hydropneumatic]] [[self-levelling suspension]] system, tested on the rear suspension of the Traction in 1954. The DS was also the first production car with modern [[disc brakes]].
A single high-pressure [[hydraulic]] system was used to actuate the [[power steering]], the [[suspension (vehicle)|suspension]] and brakes; the brakes were fully powered, not power assisted, as pedal force was not a component of braking power.
The gearshift, (semi-[[automatic transmission]]) was also powered by the hydraulic system through a control valve, with actuating pistons in the [[gearbox]] cover to shift the gears in the [[transmission (mechanics)|transmission]], and the clutch was operated automatically by the system, so there was no clutch pedal. From 1957 the ID19 model offered a simplified hydraulic system, with manual steering and conventional manual gearshift, and a significant price reduction.
From 1968, with revised front end style, the DS also introduced auxiliary driving lights, that moved directionally with the steering, improving visibility at night.
Production from 1956 to 1975 totalled almost 1.5 million cars.
The streamlined car was remarkable for its era and had a remarkable sounding name – in French, ''DS'' is pronounced {{IPA|fr|de.ɛs|}}, which sounds the same as {{lang|fr|déesse}}, which means ''[[Goddess]]''.<ref>{{cite web|url=http://www.hagerty.com/price-guide/1963-Citroen-DS~19 |title=1963 Citroen DS-19 &#124; Hagerty – Classic Car Price Guide |access-date=18 November 2014 |url-status=dead |archive-url=https://web.archive.org/web/20141129033907/http://www.hagerty.com/price-guide/1963-Citroen-DS~19 |archive-date=29 November 2014 }}</ref> It placed third in the 1999 [[Car of the Century]] competition.
[[File:Citroen near Mt. Baker ca. 1970.jpg|thumb|A DS near Mt. Baker circa. 1970]]
{{multiple image
|align     = center
|direction = horizontal
|image1    = Citroen ID19 or DS 19 mfd 1962 registered for UK roads Feb 1990 1911cc.jpg
|width1    = 227
|caption1  = 1962 [[Citroën DS|Citroën ID variant of DS]]
|image2    = 1972 Citroen DS21 headlights.jpg
|width2    = 200
|caption2  = [[Citroën DS]] Pallas with directional headlights (1968–1975)
|image3    = 2 DS Citroën.jpg
|width3    = 201
|caption3  = DS Sedan (1955–1975) and Cabriolet (1960–1971)
|image4    = Citroën DS 20, Bj. 1974 (Foto Sp 2016-06-05).JPG
|width4    = 227
}}

====High pressure hydraulics====
This high-pressure hydraulic system would form the basis of over 9 million Citroën cars, including the [[Citroën DS|DS]], [[Citroën SM|SM]], [[Citroën GS|GS]], [[Citroën CX|CX]], [[Citroën BX|BX]], [[Citroën XM|XM]], [[Citroën Xantia|Xantia]], [[Citroën C5|C5]], and [[Citroën C6|C6]]. [[Self-levelling suspension]] is the principal user benefit: the car maintains a constant ride height above the road, regardless of passenger and cargo load and despite the very soft suspension. [[Hydropneumatic suspension]] is uniquely able to [[ride quality|absorb road irregularities]] without disturbing the occupants<ref name="autotraderclassics.com">[http://www.autotraderclassics.com/car-article/Topless+Goddess+_+Citroen+DS+Décapotable-44136.xhtml Autotrader] autotraderclassics.com {{dead link|date=August 2023}}</ref> and is often compared to riding on a ''[[magic carpet]]'' for this reason.<ref>{{cite web|url=http://classics.honestjohn.co.uk/reviews/citroen/xm/ |title=Citroën XM - Classic Car Review &#124; Honest John |publisher=Classics.honestjohn.co.uk |access-date=16 July 2016}}</ref>
These vehicles shared the distinguishing feature of rising to operating [[ride height]] when the engine was turned on, like a "mechanical camel" (per ''Car & Driver'' magazine). A lever ( later replaced by an electronic switch ) beside the driver's seat allowed the driver to adjust the height of the car; this height adjustability allows for the clearing of obstacles, fording shallow (slow-moving) streams and changing tyres.

Since Citroën was underfunded, its vehicles had the tendency to be underdeveloped at launch, with limited distribution and service networks outside France. 
Consequently, the early DS models experienced teething issues with the complex hydraulic system.<ref name="autotraderclassics.com"/> Eventually, the hydraulic seals and system component design were sorted, becoming reliable.<ref>[[CAR Magazine]] August 1979 Long-Term Test CX Familiale</ref>
Licensing such a technological leap forward was pursued to a limited extent: in 1965 the [[Rolls-Royce Silver Shadow]] used this type of suspension, while the 1963 [[Mercedes-Benz 600]] and [[Mercedes-Benz 300SEL 6.3]] tried to replicate its advantages with a costly, complex and expensive to maintain, [[air suspension]], that avoided the Citroën-patented technology.<ref>{{cite web|url=http://600airsuspension.com/resources/article-on-mercedes-air-suspension-by-martin-werminghausen.pdf |last=Werminghausen |first=Martin |date=11 February 2014 |title=Mercedes Air Suspension |work=600airsuspension.com |access-date=12 January 2022}}</ref> By 1975, the [[Mercedes-Benz 450SEL 6.9]] was finally produced with this proven system and [[Mercedes-Benz]] continues to offer variations on this technology today.
During Citroën's 1968–1975 venture with [[Maserati]], the Citroën high-pressure hydraulic system was used on several Maserati models : for power clutch operation (Bora); power pedal adjustment (Bora); pop-up headlights (Bora, Merak); brakes (Bora, Merak, Khamsin); steering (Khamsin) and the entire [[Maserati Quattroporte|Quattroporte II]] prototype, which was a four-door [[Citroën SM]] under the skin.<ref name="citroencarclub.com">{{cite web|url=http://www.citroencarclub.com/drupal/node/105 |title=Citroen's Partnerships |publisher=Citroen Car Club |archive-url=https://web.archive.org/web/20141129021224/http://www.citroencarclub.com/drupal/node/105|archive-date=29 November 2014|url-status=dead}}</ref>

====Aerodynamic pioneer====
Citroën was one of the early pioneers of the now-widespread trend of [[aerodynamic]] automobile design, which helps to reduce [[fuel consumption]] and to improve high-speed performance, by reducing [[Drag coefficient|wind resistance]]. The DS could happily cruise at {{convert|160|km/h|-1|abbr=on}} without any discomfort for the occupants.<ref>{{cite web|url=http://www.citroenet.org.uk/passenger-cars/michelin/ds/05.html |title=Citroën DS a subjective view |publisher=Citroenet.org.uk |date=10 June 2000 |access-date=16 July 2016}}</ref> The firm began using a [[wind tunnel]] in the 1950s, helping them to create highly streamlined cars, like the DS, that were years ahead of their competitors, and so good were the aerodynamics of the [[Citroën CX|CX]] model, that it took its name – <math>\mathbf c_\mathrm x\,</math> – from the mathematical term used to measure the drag coefficient.

====Expansion and financial challenges====
In the 1960s, Citroën undertook a series of financial and development decisions, aiming to build on its strength of the 1950s with the successful 2CV, Type H, and DS models. Nevertheless, these maneuvers were insufficiently effective, and Citroën went bankrupt again in 1974.

These measures were to address two key gaps facing the company:
*First, the lack of a mid-size car, between its own range of very small, cheap passenger vehicles ([[Citroën 2CV|2CV]]/[[Citroën Ami|Ami]]) and the large, expensive models ([[Citroën DS|DS]]/ID).<ref name="citroencarclub.com"/> In today's terms, this would be similar to a brand consisting only of the [[Tata Nano]] and [[Jaguar XJ]]. Because of its potential volume, the mid-size segment was the most profitable part of the car market and, in 1965, the ''Citroënesque'' [[Renault 16]] stepped in to fill it.
*The second major issue was the lack of a powerful engine, suitable for export markets. The post-WW2 [[Tax horsepower]] system in France was [[Progressive tax|steeply progressive]] and vehicles over 2.0 (later 2.8) litres displacement faced a heavy annual tax, with the result that cars made in France were considered underpowered outside the country.<ref name="Citroën SM 1981">{{citation | title = Citroën SM | publisher = Osprey Autohistory | first = Jeff | last = Daniels | date = 1981 | isbn = 0-85045-381-X }}</ref> For both the 1955 [[Citroën DS|DS]] and 1974 [[Citroën CX|CX]] models, development of the original engine around which the design was planned proved too expensive for the available finances, so the actual engine used in both cases was a modest and outdated [[Straight-four engine|four-cylinder design]].<ref>{{cite web|url=http://www.citroenet.org.uk/passenger-cars/michelin/ds/01.html |title=Citroën DS prototypes The birth of a Goddess 1 |publisher=Citroenet.org.uk |date=10 June 2000 |access-date=16 July 2016}}</ref>

These steps include:
*1963 – opened negotiations with [[Peugeot]] to cooperate in the purchase of raw materials and equipment, but talks broke off in 1965.
*1964 – partnered with [[NSU Motorenwerke]] to develop the [[Wankel engine]] via the Comobil (later [[Comotor]]) subsidiary. For Citroën, this represented the chance for a technological run around the French [[Tax horsepower]] system by producing a more powerful but still small power plant. The first production car developed 106&nbsp;hp from a 1-litre engine,<ref>{{cite web |url=http://www.zeperfs.com/en/fiche2890-citroen-gs-birotor.htm |title=Citroën GS Birotor 107 hp - Specs & Performance |publisher=Zeperfs.com |date=15 November 2014 |access-date=16 July 2016 |url-status=dead |archive-url=https://web.archive.org/web/20160320191730/http://www.zeperfs.com/en/fiche2890-citroen-gs-birotor.htm |archive-date=20 March 2016 }}</ref> while the standard GS delivered 55&nbsp;hp with a 1-litre engine.<ref>{{cite web|last=Glon |first=Ronan |url=http://ranwhenparked.net/2013/10/22/a-quick-look-at-the-citroen-gs-camargue/ |title=A quick look at the Citroën GS Camargue |publisher=Ran When Parked |date=22 October 2013 |access-date=16 July 2016}}</ref>
*1965 – took over the French maker [[Panhard]] in the hope of using its expertise in mid-sized cars; cooperation between the two companies had begun twelve years earlier and they had agreed to a partial merger of their sales networks in 1953; Panhard ceased manufacturing in 1967.<ref name="citroencarclub.com"/>
*1965 – purchased the truck manufacturer [[Berliet]].<ref name="citroencarclub.com"/>
*1968 – purchased the [[Italy|Italian]] [[sports car]] [[automaker|maker]] [[Maserati]] again with an eye to producing a more powerful car, keeping a small engine in line with the French [[tax horsepower]] system.<ref name="Citroën SM 1981"/> The first production vehicle developed 170&nbsp;hp with a 2.7 litre engine,<ref>{{cite web |url=http://www.zeperfs.com/en/fiche4905-citroen-sm-v6-2-7-c.htm |title=Citroën SM V6 2.7 c 170 hp - Specs & Performance |publisher=Zeperfs.com |date=6 April 2015 |access-date=16 July 2016 |url-status=dead |archive-url=https://web.archive.org/web/20160806185957/http://www.zeperfs.com/en/fiche4905-citroen-sm-v6-2-7-c.htm |archive-date=6 August 2016 }}</ref> this was the 1970 [[Citroën SM|SM]], which featured a V6 Maserati power plant, [[hydropneumatic suspension]]  and a fully powered, self-centering steering system called [[DIRAVI]]; the SM was engineered as if it were replacing the [[Citroën DS|DS]] family car, a level of investment that the small luxury [[Grand tourer|Grand Touring car]] sector alone would never be able to support, even in the best of circumstances.
*1968 – restructured worldwide operations under a new holding company, Citroën SA. [[Michelin]], Citroën's longtime controlling shareholder, sold a 49% stake to [[Fiat]] in what was referred to as the ''PARDEVI'' agreement (Participation et Développement Industriels).<ref name="citroencarclub.com"/>

The teams of Charles Marchetti and Citroën began working together on the development of the {{Interlanguage link|Citroën RE-2|fr|3=Citroën RE-2|lt=RE-2}} [[helicopter]].

From a model range perspective, the 1970s started well, supported by the successful launch of the long-awaited mid-size [[Citroën GS]], finally filling the huge gap between the 2CV and the DS – with a 1-litre, [[Hydropneumatic suspension|hydropneumatically suspended]] car. The GS went on to sell 2.5 million units; 601,918 cars were produced in 1972 alone, up from the 526,443 of 1971, and enough to lift the company past [[Peugeot]] into second place among French auto makers when ranked by sales volume.<ref name=Automobilia1972>{{cite journal| title =Automobilia| journal = Toutes les Voitures Françaises 1972 (Salon [Oct] 1971)| volume = 76s| page =19|year = 2005|publisher=Histoire & collections|location=Paris }}</ref> The older models continued to sell well: the peak production period of the DS was 1970, and [[Citroën 2CV|2CV]] was in 1974.

As the 1970s progressed, circumstances became more unfavourable. In 1973, [[Fiat]] sold back to Michelin its 49% stake in the ''PARDEVI'' holding company that owned Citroën, the Citroën and Fiat joint announcement indicated that the benefits foreseen for their union in 1968 had failed to materialise.<ref name=Automobilia1974>{{cite journal| title =Automobilia| journal = Toutes les Voitures Françaises 1975 (Salon Paris Oct 1974)| volume = 72| page =19|year = 2005|publisher=Histoire & collections|location=Paris }}</ref> This was not in line with the tyre company's long-term strategy of ending involvements in the car manufacturing business and created a very unstable ownership situation.<ref name="citroenet.org.uk">{{cite web|first=Julian | last = Marsh |url=http://www.citroenet.org.uk/miscellaneous/history/history03.html |title=A Brief History of Citroën Page 3 |publisher=Citroenet.org.uk |access-date=16 July 2016}}</ref> The company suffered another financial blow with the [[1973 energy crisis]]. The gamble on [[Comotor]] and [[Maserati]] showed that there was a serious flaw with the plan particularly for companies producing engines with high fuel consumption.

In 1974, the carmaker withdrew from North America due to U.S. design regulations that outlawed core features of Citroën cars (see [[Citroën SM]]).

Huge losses at Citroën were caused by the failure of the [[Comotor]] rotary engine venture added to the [[strategic management|strategic management error]] of going the {{val|15|u=years}} from 1955 to 1970 without a model in the profitable middle range of the European market, plus the massive development costs a string of new models: the [[Citroën GS|GS]], [[Citroën GS Birotor|GS Birotor]], [[Citroën CX|CX]], [[Citroën SM|SM]], [[Maserati Bora]], [[Maserati Merak]], [[Maserati Quattroporte II]], and [[Maserati Khamsin]]. Each of these models is a technological marvel in its own right.
Thus, forty years after the bankruptcy related to the [[Traction Avant]], Citroën went bankrupt again, losing its existence as an independent entity; selling Berliet and Maserati and closing Comotor.<ref name="citroencarclub.com"/>

{{multiple image
| align     = center
| direction = horizontal
| image1    = Citroen-SM-Gendarmerie.jpg
| width1    = 245
| caption1  = [[Citroën SM]]
| image2    = MASERATI KHAMSIN PROFIL ARRIERE.JPG
| width2    = 218
| caption2  = [[Maserati Khamsin]]
| image3    = Citroën GS Birotor (front).jpg
| width3    = 220
| caption3  = [[Citroën GS|Citroën GS Birotor]] and [[Citroën C6]]
| image4    = 1982 Citroen CX Prestige.jpg
| width4    = 160
| caption4  = [[Citroën CX]], the 1975 Car of the Year in Europe
}}