Editing Variable displacement (section)

==={{anchor|Mitsubishi|MD}} Mitsubishi MD===
In 1982 [[Mitsubishi Motors|Mitsubishi]] developed its own variable displacement in the form of MD (Modulated Displacement) which proved that the technology, first used in Mitsubishi's 1.4 L [[Mitsubishi Orion engine|4G12]] [[Inline-four engine|straight-four]] engine, can function successfully.<ref>{{cite web|url=http://www.mitsubishi-motors.com/corporate/museum/history/1980/e/index.html |title="Mitsubishi Motors Web Museum", Mitsubishi Motors website |url-status=dead |archive-url=https://web.archive.org/web/20110716131014/http://www.mitsubishi-motors.com/corporate/museum/history/1980/e/index.html |archive-date=2011-07-16 }}</ref> Because Cadillac's system proved to be a failure and a four-cylinder engine was used, Mitsubishi hailed their own as a world first.<ref name="GDI">{{cite web|url=http://www.mitsubishi-motors.co.za/featuresites/mm_history/GDI.asp|title="Mitsubishi Motors History", Mitsubishi Motors South Africa website|access-date=2007-03-12|archive-url=https://web.archive.org/web/20070125232459/http://www.mitsubishi-motors.co.za/featuresites/mm_history/GDI.asp|archive-date=2007-01-25|url-status=dead}}</ref> The technology was later used in Mitsubishi's V6 engines.<ref name="mivec">[http://autospeed.drive.com.au/cms/A_2651/article.html "Mountain of MIVECs"] {{Webarchive|url=https://web.archive.org/web/20070505233011/http://autospeed.drive.com.au/cms/A_2651/article.html |date=2007-05-05 }}, Michael Knowling, ''AutoSpeed'', Issue 346, September 3, 2005</ref>

The system worked by disabling the valves on cylinders number 1 and 4 at speeds below {{convert|70|km/h|mph|1|abbr=on}}, at idling, and while decelerating. Fuel consumption figures were generally about 20 percent improved over the regular 4G12 engine.<ref name=sae362>{{cite journal | ref = oMD | last1 = Fukui | first1 = Toyoaki | first2 = Tatsuro | last2 = Nakagami | first3 = Hiroyasu | last3 = Endo | first4 = Takehiko | last4 = Katsumoto | first5 = Yoshiaki | last5 = Danno | title = Mitsubishi Orion-MD — A New Variable Displacement Engine | journal = SAE Transactions | volume = 92, section 3 | date = 1983 | pages = 362–370 | jstor = 44647614 }}</ref> Period sources, however, complained about the engine running very roughly while in two-cylinder mode, despite special engine mounts with hydraulic damping.<ref name=AC4459a>{{cite magazine | ref = JH1 | magazine = [[Autocar (magazine)|Autocar]] | title = Putting on the pressure | first = John | last = Hartley | publisher = IPC Business Press Ltd. | pages = 35–36 | date = 1982-06-05 | volume = 156 | number = 4459 }}</ref> Other efforts taken to minimize vibrations and harshness included a section of flexible exhaust pipe, not operating the system until the coolant temperature reached 70C, and a 70 percent heavier flywheel.<ref name=sae367>[[#oMD|Fukui ''et al'']], p.367</ref> Mitsubishi's effort remained short-lived, mainly because of a lack of response from car buyers.<ref name="higbee">{{cite news|last=Higbee|first= Arthur|date=20 November 1992|url=https://www.nytimes.com/1992/11/20/news/20iht-topi_17.html|title=Mitsubishi Engine Switches Cylinders|work= [[The New York Times]]|access-date=28 October 2013}}</ref>

In 1993, a year after Mitsubishi developed its own [[variable valve timing]] technology, the [[MIVEC]]-MD variant was introduced. The revived MD technology was now in its second generation with improved electronic engine controls enabling the switch from 4 to 2 cylinders to be made almost imperceptibly. In MD mode, the MIVEC engine utilizes only two of its four cylinders, which reduces significantly the energy wasted due to pumping losses. In addition, power loss due to engine friction is also reduced.<ref name="GDI"/> Depending on conditions, the MIVEC-MD system can reduce fuel consumption by 10–20 percent; although some of this gain is from the variable valve timing system, not from the variable-displacement feature.<ref name="mivec"/> Modulated Displacement was dropped around 1996.<ref name="mivec"/>