Editing Citroën (section)

====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>