View source for List of Subaru engines

{{Short description|none}}
[[Subaru]] uses a four or five character code to identify all of their [[Internal combustion engine|engines]].<ref name=autospeed>{{cite news | title = 2004 Engine Epic - Subaru Engines | author = Michael Knowling | url = http://www.autospeed.com/cms/A_2093/printArticle.html | work = AutoSpeed Magazine | date = April 2, 2004 | access-date = 2009-06-30 | archive-date = 2008-08-25 | archive-url = https://web.archive.org/web/20080825060129/http://autospeed.com/cms/A_2093/printArticle.html | url-status = dead }}</ref> As of August 2022 these are the engines presently in models sold by Subaru
* FB20D: 1995&nbsp;cc [[Double overhead camshaft|DOHC]], 2017+ [[Subaru Impreza]], and 2018+ [[Subaru Crosstrek]]
* FB25D: 2498&nbsp;cc [[Double overhead camshaft|DOHC]], 2019+ North American [[Subaru Forester]], 2020+ North American [[Subaru Legacy]], 2020+ North American [[Subaru Outback]], and 2021+ North American [[Subaru Crosstrek]]
* FA24D: 2,387&nbsp;cc [[Dual overhead camshaft|DOHC]], 2022+ [[Toyota 86|Subaru BRZ/Toyota 86]]
* FA24F: 2,387&nbsp;cc [[Dual overhead camshaft|DOHC]], turbo, 2019+ USDM [[Subaru Ascent]], 2020+ [[Subaru Legacy]], and 2020+ [[Subaru Outback]]. 2021+ USDM [[Subaru WRX]]
* CB18: 1795&nbsp;cc [[Double overhead camshaft|DOHC]], 2020 JDM [[Subaru Levorg#2020|Subaru Levorg]], 2021 JDM [[Subaru Forester#SK|Subaru Forester]]


==Two-cylinder==

=== {{anchor|EK}} Subaru EK engine ===
[[File:Gasoline Engine Type EK31 2C Subaru.jpg|thumb|EK31]]
[[File:Gasoline Engine Type EK23 Subaru with 4th Sambar.jpg|thumb|The late 1980s EK23, with three valves per cylinder]]

The EK series was an inline twin cylinder engine. Early versions were air-cooled [[Two-stroke engine|two-stroke cycle]], later replaced with water-cooled configurations in 1971. The engine was upgraded to a [[Four-stroke engine|four-stroke]] [[SOHC]] in 1973 to meet Japanese Government emission regulations, using the SEEC emissions system (later SEEC-T), with an alloy block and head.<ref>{{cite journal | title = Automobil Revue '74 | editor1-last = Braunschweig | editor1-first = Robert | publisher = Hallwag SA | page = 483 | location = Berne, Switzerland | volume = 69 | date = March 14, 1974 |display-editors=etal}}</ref>

The '''({{langx|ja|[[:ja:スバル・EK型エンジン|Subaru EK series]]}})''' was used from 1958 until 1989 in most [[Kei car]] models.

{|class="wikitable sortable" style=text-align:center;font-size:90%;
|+ Subaru EK engine summary
|-
!Cooling
!Stroke
!Name !! Displacement !! Bore × Stroke !! colspan=2 | Output !! Compression Ratio !! Applications
|-
| rowspan=10 style=background:#ddd; | Air
| rowspan=15 | [[Two-stroke engine|Two]]
! rowspan=3 | {{anchor|EK31}}EK31
| rowspan=3 | {{convert|356|cm3|abbr=on}} || rowspan=3 | {{convert|61.5|×|60.0|mm|abbr=on}}
| {{convert|16|PS|kW hp|abbr=on}} at 4,500&nbsp;rpm || {{dts|1958|05|abbr=on}}–{{dts|1960|02|abbr=on}}
| rowspan=4 | 6.5:1
| rowspan=3 | [[Subaru 360]] (1958–68)<br/>[[Subaru Sambar|Sambar]] (1961–70)
|-
| {{convert|18|PS|kW hp|abbr=on}} at 4,700&nbsp;rpm || {{dts|1960|02|abbr=on}}–{{dts|1964|07|abbr=on}}
|-
| {{convert|20|PS|kW hp|abbr=on}} at 5,000&nbsp;rpm || {{dts|1964|07|abbr=on}}–{{dts|1968|08|abbr=on}}
|-
! rowspan=1 | {{anchor|EK51}}EK51
| rowspan=1 | {{convert|423|cm3|abbr=on}} || rowspan=1 | {{convert|67.0|×|60.0|mm|abbr=on}}
| colspan=2 | {{convert|23|PS|kW hp|abbr=on}} at 5,000&nbsp;rpm
| rowspan=1 | [[Subaru 360|Subaru 450 (MAIA)]] Japan & North America (1960–66)
|-
! rowspan=2 | {{anchor|EK32}}EK32
| rowspan=11 | {{convert|356|cm3|abbr=on}} || rowspan=11 | {{convert|61.5|×|60.0|mm|abbr=on}}
| {{convert|25|PS|kW hp|abbr=on}} at 5,500&nbsp;rpm || {{dts|1968|08|abbr=on}}–{{dts|1970|abbr=on}}
| rowspan=1 | 7.5:1
| rowspan=2 | [[Subaru 360]] and 360 Young SS (1968-70)
|-
| {{convert|36|PS|kW hp|abbr=on}} at 7,000&nbsp;rpm || {{dts|1968|11|abbr=on}}–{{dts|1970|abbr=on}}
|-
! rowspan=4 | {{anchor|EK33}}EK33
| {{convert|26|PS|kW hp|abbr=on}} at 5,800&nbsp;rpm || R-2 Van ''K41'', Sambar ''K55/K64''
| rowspan=2 | 6.5:1
| rowspan=4 | [[Subaru R-2]] (1969–71)<br/>[[Subaru Sambar]] (1970–73)
|-
| {{convert|30|PS|kW hp|abbr=on}} at 6,500&nbsp;rpm || R-2
|-
| {{convert|36|PS|kW hp|abbr=on}} at 7,000&nbsp;rpm || R-2 SS
| rowspan=2 | 7.5:1
|-
| {{convert|32|PS|kW hp|abbr=on}} at 6,500&nbsp;rpm || R-2 Sport Edition
|-
| rowspan=21 style=background:#aaf; | Water
! rowspan=5 | {{anchor|EK34}}EK34
| {{convert|28|PS|kW hp|abbr=on}} at 5,500&nbsp;rpm || Sambar ''K71/K72/K81''
| rowspan=5 | 6.5:1
| rowspan=5 | [[Subaru R-2]] 1971.10-1972.07<br/>[[Subaru Rex]] 1972.07-1973.10<br/>[[Subaru Sambar]] 1973.02-1976.02
|-
| {{convert|32|PS|kW hp|abbr=on}} at 6,000&nbsp;rpm || R-2, Rex
|-
| {{convert|35|PS|kW hp|abbr=on}} at 6,500&nbsp;rpm || Rex TS
|-
| {{convert|36|PS|kW hp|abbr=on}} at 7,000&nbsp;rpm || R-2 GSS
|-
| {{convert|37|PS|kW hp|abbr=on}} at 6,500&nbsp;rpm || Rex GSR
|-
| rowspan=16 | [[Four-stroke engine|Four]]
! rowspan=2 | {{anchor|EK21}}EK21
| rowspan=2 | {{convert|358|cm3|abbr=on}} || rowspan=2 | {{convert|66.0|×|52.4|mm|abbr=on}}
| {{convert|31|PS|kW hp|abbr=on}} at 8,000&nbsp;rpm || Rex 73.10-75.12
| rowspan=2 | 9.5:1
| rowspan=2 | [[Subaru Rex]] ''K22'' 1973.10–1976.05<br/>[[Subaru Sambar]] 1976.02–1976.05
|-
| {{convert|28|PS|kW hp|abbr=on}} at 7,500&nbsp;rpm || Rex Van ''K42'', Wagon ''K26'', Rex sedan 75.12-76.05
|-
! rowspan=2 | {{anchor|EK22}}EK22{{efn|SEEC-T emissions system}}
| rowspan=2 | {{convert|490|cm3|abbr=on}} || rowspan=2 | {{convert|74.0|×|57.0|mm|abbr=on}}
| {{convert|28|PS|kW hp|abbr=on}} || Rex 5 Van ''K43'', Sambar 5 ''K75/76/85''
| rowspan=2 | 9.0:1
| rowspan=2 | [[Subaru Rex]] 1976.05–1977.05<br/>[[Subaru Sambar]] 5 1976.05–1977.03
|-
| {{convert|31|PS|kW hp|abbr=on}} at 6,500&nbsp;rpm || Rex 5 ''K23''
|-
! rowspan=4 | {{anchor|EK23}}EK23 (2V){{efn|name=2V|Two valves per cylinder}}
| rowspan=9 | {{convert|544|cm3|abbr=on}} || rowspan=9 | {{convert|76.0|×|60.0|mm|abbr=on}}
| {{convert|31|PS|kW hp|abbr=on}} at 6,200&nbsp;rpm || Rex
| rowspan=4 | 8.5:1
| rowspan=4 | [[Subaru Rex]] (1977.05–1989)<br/>[[Subaru Sambar]] (1977–90)
|-
| {{convert|28|PS|kW hp|abbr=on}} at 6,200&nbsp;rpm || Rex Van, Sambar
|-
| {{convert|31|PS|kW hp|abbr=on}} at 6,000&nbsp;rpm || Rex 2nd gen & Rex Combi
|-
| {{convert|30|PS|kW hp|abbr=on}} at 6,000&nbsp;rpm || Rex 3rd gen
|-
! rowspan=2 | {{anchor|EK23 ThreeValve}}EK23 (3V){{efn|name=3V|Three valves per cylinder: two intake, one exhaust}}
| {{convert|34|PS|kW hp|abbr=on}} at 6,000&nbsp;rpm || Sambar
| rowspan=2 | 9.0:1
| rowspan=2 | [[Subaru Rex]] Viki (1986–89)<br/>[[Subaru Sambar]] (1989–90)
|-
| {{convert|36|PS|kW hp|abbr=on}} at 7,000&nbsp;rpm || Rex
|-
! rowspan=1 | {{anchor|EK23 Turbo}}EK23 (2V-T){{efn|name=2V}}{{efn|name=Turbo|Turbocharged: Hitachi-made, 36&nbsp;mm turbines}}
| colspan=2 | {{convert|41|PS|kW hp|abbr=on}} at 6,000&nbsp;rpm
| rowspan=1 | 8.5:1
| rowspan=1 | [[Subaru Rex]] Combi (1983–86)
|-
! rowspan=1 | {{anchor|EK23 ThreeValve Turbo}}EK23 (3V){{efn|name=3V}}{{efn|name=Turbo}}
| colspan=2 | {{convert|36|PS|kW hp|abbr=on}} at 7,000&nbsp;rpm
| rowspan=2 | 9.0:1
| rowspan=1 | [[Subaru Rex]] VX (1986–89)
|-
! rowspan=1 | {{anchor|EK23SC}}EK23 (SC){{efn|name=3V}}{{efn|Supercharged, water-cooled intercooler}}
| colspan=2 | {{convert|55|PS|kW hp|abbr=on}} at 6,400&nbsp;rpm
| rowspan=1 | [[Subaru Rex]] Supercharger (1988–89)
|-
! rowspan=4 | {{anchor|EK42}}EK42{{efn|name=2V}}
| rowspan=8 | {{convert|665|cm3|abbr=on}} || rowspan=8 | {{convert|78.0|×|69.6|mm|abbr=on}}
| {{convert|31|PS|kW hp|abbr=on}} || 700
| rowspan=4 | 9.5:1
| rowspan=4 | [[Subaru Rex]] and [[Subaru Sambar|Sambar/700]] (export only, 1982–89)

|-
| {{convert|37|PS|kW hp|abbr=on}} at 6,400&nbsp;rpm || low octane version
|-
| {{convert|35|PS|kW hp|abbr=on}} at 6,400&nbsp;rpm || M70, Mini Jumbo, Sherpa (high octane version)
|}

;Notes
{{notelist}}

==Three-cylinder==
The EF series engine is a liquid-cooled three-cylinder, [[Four-stroke engine|four-stroke]], with [[SOHC]]. It is not compliant with Japanese Government regulations concerning displacement of [[kei cars]] with a current maximum limit of 660&nbsp;cc. The EF appeared while the EK was being replaced by the EN05.

[[Image:EF12engine.JPG|thumb|right|200px|Subaru EF-12 Engine]]

=== [[Subaru EF engine]]===
* EF10: Bore x Stroke mm = 78.0 x 69.6
*Piston displacement = 997&nbsp;cc
*Compression ratio = 9.5:1
*Two valves per cylinder
[[SOHC]] 2V, 55&nbsp;hp at 5,200&nbsp;rpm 1984–1987 [[Subaru Justy]]
* EF12:Bore x Stroke mm = 78.0 x 83.0
*Piston displacement = 1189&nbsp;cc
*Compression ratio = 9.1:1
*Three valves per cylinder
[[SOHC]] 3V, 66-73&nbsp;hp 1987–1994 [[Subaru Justy]]

==Four-cylinder==
All of Subaru's four-cylinder engines (except the '''EN series''') are liquid-cooled, horizontally opposed [[Flat-4|boxer]] [[Four-stroke engine|four-stroke]]s.

=== [[Subaru EA engine]] ===
The EA was used from 1966 until 1994 in most models. It is a basic two-valve-per-cylinder design with siamese ports, or one port that is directly next to another, and three main [[crankshaft]] [[main bearing]]s. Engines with [[overhead camshaft]]s were installed with two timing belts, whereas vehicles with overhead valves used timing gears exclusively.
[[File:Subaru EA82 Leone 1989.jpg|thumb|right|200px|Subaru EA82 Engine]]
* EA52: 977&nbsp;cc [[Overhead valve|OHV]], 55&nbsp;hp at 6,000&nbsp;rpm used in the 1966–1971 [[Subaru 1000]]
* EA61: 1088.8&nbsp;cc [[Overhead valve|OHV]], 62&nbsp;hp at 6,400&nbsp;rpm used in the 1970–1972 [[Subaru FF-1 Star]] and [[Subaru G]]
* EA62: 1267.5&nbsp;cc [[Overhead valve|OHV]], 80&nbsp;hp at 6,400&nbsp;rpm used in the 1971–1972 [[Subaru G]]
* EA63: 1362&nbsp;cc [[Overhead valve|OHV]], 58&nbsp;hp at 5,200&nbsp;rpm used in the 1973–1976 [[Subaru Leone]]
* EA71: 1595&nbsp;cc [[Overhead valve|OHV]], 67&nbsp;hp at 5,200&nbsp;rpm or 68 at 4,800&nbsp;rpm used in the 1976–1987 [[Subaru Leone]] and 1978–1980 [[Subaru BRAT]]/brumby
* EA81: 1781&nbsp;cc [[Overhead valve|OHV]], 73&nbsp;hp at 4,800&nbsp;rpm used in the 1980–1984 [[Subaru Leone]] and 1981–1993 [[Subaru BRAT]]/brumby
* EA81T: 1781&nbsp;cc [[Overhead valve|OHV]] [[Turbocharger|Turbo]], 95&nbsp;hp at 4,200&nbsp;rpm used in the 1983–1984 [[Subaru Leone]] and [[Subaru BRAT]]/brumby
* EA82: 1791&nbsp;cc [[SOHC]], 84-97&nbsp;hp used in the [[Subaru Leone]] and [[Subaru XT]]
* EA82T: 1791&nbsp;cc [[SOHC]], 136&nbsp;hp at 5200&nbsp;rpm used in the [[Subaru Leone]] and [[Subaru XT]]

=== {{anchor|EE|diesel}} Subaru EE engine (diesel)===
[[File:Subaru Boxer Diesel engine for 2008 Legacy in Eco-Products 2008.jpg|thumb|right|upright|Subaru EE20 (2008)]]
Subaru unveiled the world's first boxer [[diesel engine]] to be fitted in a passenger car at the Geneva Auto Show in 2007.<ref>{{cite press release |url=https://www.subaru.co.jp/en/news/archives/press/2007/07_02_08e.html |title=Exhibition Outlines of the 77th Geneva International Motor Show: FHI to unveil the "SUBARU BOXER TURBO DIESEL" engine |date=8 February 2007 |publisher=Fuji Heavy Industries Ltd |access-date=28 August 2018}}</ref> This 2.0L [[Double overhead camshaft|DOHC]] engine, designated the EE20,<ref>{{cite web|url= http://jalopnik.com/383023/the-new-subaru-ee20-boxer-turbo-diesel-in-detail |last=Wojdyla | first = Ben |publisher= Jalopnik |title= The New Subaru EE20 Boxer Turbo Diesel, In Detail |date=2008-04-23 |access-date=2010-12-08}}</ref> has an output of {{convert|110|kW|PS hp|abbr=on}} at 3600&nbsp;rpm and develops {{convert|350|Nm|kgm lbft|abbr=on}} of torque at 1800&nbsp;rpm,<ref name=TechOn /><ref>{{cite web |url=https://www.subaru-global.com/technology/performance/drivetrain_boxerengine.html |title=Technology: Performance — The Subaru Boxer Engine |publisher=Subaru Global |access-date=8 April 2016 |archive-url=https://web.archive.org/web/20160408123730/http://www.subaru-global.com/technology/performance/drivetrain_boxerengine.html |url-status=dead |archive-date=8 April 2016 }}</ref> with a redline of 4750&nbsp;rpm.<ref name=MTZ-mag /> The engine has a total displacement of {{convert|1998|cc|cuin|0|abbr=on}} from a square {{convert|86|×|86|mm|abbr=on}} bore x stroke with a compression ratio of 16.3:1 and uses five main bearings. The EE20 shares a bore pitch dimension and assembly line with the EZ30 at the Ooizumi Factory; compared to the contemporaneous gasoline EJ20, which has a similar displacement, the EE20 is {{convert|61.3|mm|abbr=on}} shorter.<ref name=TechOn />

The [[common rail]] solenoid injector is manufactured by [[Denso]] and operates at {{convert|180|MPa|psi|abbr=on}}.<ref name=TechOn /> The [[IHI Corporation|IHI]] variable geometry turbo is mounted under the right side of the engine, close to the exhaust manifold, reducing turbo lag.<ref name=MTZ-mag /><ref name=TechOn /> For the Legacy 2.0D, Subaru claimed consumption improved by 15 to 20% (ranging from {{convert|6.4|to|5.6|L/100km|mpgus|abbr=on}}) and that {{chem|C|O|2|link=carbon dioxide}} emissions fell from {{convert|202|to|148|g/km|lb/mi|abbr=on}} compared to the similar model with a gasoline engine.<ref name=MTZ-mag>{{cite magazine |url=https://www.fsb.unizg.hr/miv/MSUI/KonMot/Uravnotezavanje/Podloge_klipni_mehanizam/Subaru/MTZ-2008-09_Subaru%20Boxer%20Diesel_(engl.).pdf |title=Subaru Boxer Diesel: First Four-Cylinder Horizontally-Opposed Diesel Engine |author=Harima, Kenji |date=September 2008 |volume=69 |magazine=MTZ |pages=38–45 |access-date=28 August 2018}}</ref><ref name=NewEfforts>{{cite web |url=https://www.subaru.co.jp/en/csr/report/pdf/2009/e_02.pdf |title=Feature Article 4: Subaru's Approaches to Prevention of Global Warming, and Efforts in Product Development |date=2009 |publisher=Fuji Heavy Industries Ltd |access-date=28 August 2018 |page=17}}</ref>

Fuji Heavy Industries (FHI) spent three years starting in fall 2005 developing the EE20 after concluding the marque needed a diesel engine to compete in Europe.<ref name=NewEfforts /> Details about the engine were first released in February 2008,<ref name=TechOn>{{cite news |url=https://tech.nikkeibp.co.jp/dm/english/NEWS_EN/20080222/147866/ |title=FHI Details World's First Horizontally Opposed Diesel for Passenger Cars |author=Momota, Kenji |date=22 February 2008 |work=TechOn |publisher=Nikkei Business Publications |archive-date=12 February 2018 |archive-url=https://web.archive.org/web/20180212165236/https://tech.nikkeibp.co.jp/dm/english/NEWS_EN/20080222/147866/ |url-status=dead}}</ref> after an additional preview at [[Frankfurt Motor Show|Frankfurt]] in 2007,<ref>{{cite press release |url=https://www.subaru.co.jp/en/news/archives/press/2007/07_08_09e.html |title=Fuji Heavy Industries Unveils New Subaru Vehicles at the 62nd Frankfurt Motor Show |date=9 August 2007 |publisher=Fuji Heavy Industries Ltd |access-date=28 August 2018}}</ref> and an official announcement of applications was made at [[Geneva Motor Show|Geneva]] in March 2008.<ref>{{cite press release |url=https://www.subaru.co.jp/en/news/archives/press/2008/08_02_08e.html |title=Exhibition Outlines of the 78th Geneva International Motor Show: The World's First SUBARU BOXER DIESEL debuts with the Legacy/Outback |date=8 February 2008 |publisher=Fuji Heavy Industries Ltd |access-date=28 August 2018}}</ref><ref>{{cite press release |url=https://www.media.subaru-global.com/data/en/08_03_07_02e.pdf |title=Press information for the SUBARU BOXER DIESEL (Subaru Legacy/Outback 2.0D) |date=7 March 2008 |publisher=Fuji Heavy Industries Ltd |access-date=28 August 2018}}</ref>

The EE20 was originally released with [[European emission standards|Euro-4 emissions]] compliance; an [[oxidation catalyst]] and [[diesel particulate filter]] are mounted close to the turbo, using heat from exhaust gases, and the [[exhaust gas recirculation]] system is water-cooled to meet regulations.<ref name=TechOn /> The compliance was soon updated to Euro-5<ref>{{cite web|url= https://subdiesel.wordpress.com/boxer-diesel/ee20-engine-info|publisher= Subaru Diesel Crew|title= EE20 Engine Info|access-date= 2015-03-17|archive-date= 2016-03-15|archive-url= https://web.archive.org/web/20160315040318/https://subdiesel.wordpress.com/boxer-diesel/ee20-engine-info/|url-status= dead}}</ref> and Euro-6 in 2015.

;Availability
Per the March 2008 announcement at Geneva, the EE20 was sold in Legacy (wagon and sedan) and Outback vehicles for the European market; the diesel was only offered with a [[manual transmission]] at first, and the [[clutch]] and [[flywheel]] were specifically modified for diesel use.<ref name=TechOn /> In September 2008, FHI announced the EE20 would be available as a slightly modified variant (the diesel particulate filter was now closed) in Forester and Impreza models sold in Europe starting that fall. For the Forester, output was reduced slightly to {{convert|108|kW|PS bhp|abbr=on}}.<ref>{{cite press release |url=https://www.subaru.co.jp/en/news/archives/press/2008/08_09_05e.html |title=Fuji Heavy Industries Will Unveil Subaru Forester and Impreza Models with Subaru Boxer Diesel at the 2008 Paris Motor Show |date=5 September 2008 |publisher=Fuji Heavy Industries Ltd |access-date=28 August 2018}}</ref>

The EE20 was offered with the Impreza XV at that model's launch in 2010.<ref>{{cite press release |url=https://www.subaru.co.jp/en/news/archives/press/2010/10_02_05e.html |title=Exhibition Outline of the 80th Geneva International Motor Show |date=5 February 2010 |publisher=Fuji Heavy Industries Ltd |access-date=28 August 2018}}</ref> The Subaru [[continuously variable transmission]] (branded [[List of Subaru transmissions#Subaru Lineartronic CVT TR690 and TR580|Lineartronic]]) was offered as an option for EE20-equipped Outback models starting in 2013,<ref>{{cite press release |url=https://www.subaru.co.jp/en/news/archives/press/2012/13_02_07e_1_86983.html |title=Exhibition Outline of the 83rd Geneva International Motor Show |date=7 February 2013 |publisher=Fuji Heavy Industries Ltd |access-date=28 August 2018}}</ref> and sales of the Lineartronic EE20 Outback would start in Australia later in 2013.<ref>{{cite press release |url=https://www.subaru.co.jp/en/news/archives/press/2013/13_04_08e_87802.html |title=Subaru's North American Unit Sales Hit All-Time High in FY2013 - All-Time Monthly Sales Records Set in US, Canada and Australia in March - |date=8 April 2013 |publisher=Fuji Heavy Industries Ltd |access-date=28 August 2018}}</ref> At Geneva 2013, the diesel boxer was combined with three electric motors to form the hybrid powertrain of the [[Subaru VIZIV]] Concept.<ref>{{cite press release |url=https://www.subaru.co.jp/en/news/archives/press/2013/13_03_05e_2_87288.html |title=World Premiere of the "SUBARU VIZIV CONCEPT" at the 2013 Geneva Motor Show |date=5 March 2013 |publisher=Fuji Heavy Industries Ltd |access-date=28 August 2018}}</ref> The Lineartronic EE20 powertrain was added to the Forester in 2015.<ref>{{cite press release |url=https://www.subaru.co.jp/press/news-en/2015_02_06_282/ |title=Exhibition Outline of the 85th Geneva International Motor Show |date=6 February 2015 |publisher=Fuji Heavy Industries Ltd |access-date=28 August 2018}}</ref>

In 2016, citing increasingly stringent emissions standards, the project manager for the Impreza stated that further development of the EE20 had been halted.<ref>{{cite news |url=https://www.whichcar.com.au/car-news/subaru-diesels-and-six-cylinder-engines-on-the-endangered-list |title=Subaru diesels and six cylinder engine on the endangered list |author=O'Kane, Tony |date=15 September 2016 |work=WhichCar |access-date=28 August 2018}}</ref> In September 2017, Subaru announced production of diesel automobiles would end by 2020; at the time, sales were approximately 15,000 diesel-powered cars annually in Europe and Australia. The capacity gained would be used to start producing [[plug-in hybrid]]s in 2018 and electric vehicles by 2021.<ref>{{cite news |url=https://www.japantimes.co.jp/news/2017/09/07/business/corporate-business/subaru-idle-diesel-output-2020-amid-global-shift-evs |title=Subaru to idle diesel output in 2020 amid global shift to EVs |agency=Kyodo |date=7 September 2017 |newspaper=Japan Times |access-date=28 August 2018}}</ref> At Geneva in March 2018, Subaru UK confirmed its parent company's plans to discontinue diesel production, but had enough stock on hand to meet projected demand through the end of 2018.<ref>{{cite news |url=https://www.autoexpress.co.uk/subaru/102894/end-of-the-road-for-diesel-subarus |title=End of the road for diesel Subarus |author=Milne, Stuart |date=7 March 2018 |work=AutoExpress |access-date=28 August 2018}}</ref>

=== [[Subaru EJ engine]]===
The EJ engine was introduced in the 1989 [[Subaru Legacy]] to replace the EA engines. It was designed from scratch with five main crankshaft bearings and four valves per cylinder and can be either [[SOHC]] or [[Double overhead camshaft|DOHC]] and one [[timing belt (camshaft)|timing belt]]. The fifth digit is the only way to tell without seeing the engine.
[[File:Subaru EJ20G.jpg|thumb|right|200px|Subaru EJ20G twin turbo]]
* EJ15: 1483.4&nbsp;cc [[SOHC]], 1990–2003 JDM [[Subaru Impreza]]  
* EJ16: 90&nbsp;hp at 5,600&nbsp;rpm used in the 1993–2006 [[Subaru Impreza]]
* EJ18: 1820&nbsp;cc [[SOHC]] 110&nbsp;hp at 5,600&nbsp;rpm used in the 1993–1996 [[Subaru Impreza]] and Euro and JDM [[Subaru Legacy]]
* EJ20: 1994.3&nbsp;cc, available in Australia, Europe and Japan [[naturally aspirated]] at 115–190&nbsp;hp and with a [[Turbocharger|Turbo]] 220–280&nbsp;hp used on Most Models, (2002–2005 WRX in the United States)
* EJ22: 2212&nbsp;cc, 135–280&nbsp;hp used in the 1989–2001 [[Subaru Impreza]] and [[Subaru Legacy]]
* EJ25: 2457&nbsp;cc, 165–320&nbsp;hp found in Most Models 1995–Present
* EJ30: Special limited engine.  Four were built by Subaru, but only 3 remain in working condition.  There is no readily available technical or power information on these engines.

Generally the EJ-series can be divided into two versions: the Phase I engines (1989–1998) and the Phase II engines (1999–2010). The Phase II engines featured new cylinder heads and crankshafts with the thrust bearing located at crank bearing #5 instead of #3. The designation also changed from Phase I to Phase II. All Phase I engines have an alphanumerical suffix behind the standard EJXX designation, all Phase II engines have a numerical suffix behind the EJXX designation. Example:

Phase I:
EJ15E, EJ15J, EJ16E, EJ18E, EJ20B, EJ20D, EJ20E, EJ20G, EJ20H, EJ20J, EJ20R, EJ20K, EJ22E, EJ221, EJ25D

Phase II:
EJ151, EJ161, EJ181, EJ201, EJ202, EJ203, EJ204, EJ205, EJ206, EJ207, EJ208, EJ222, EJ251, EJ252, EJ253, EJ254, EJ255, EJ257, EJ20X, EJ20Y

*''There's at least 3 exceptions from this rule - MY'07 EJ20F engine. Most likely F stands for bi-Fuel (engines prepared for LPG). This engine model has reinforced engine valves. This is unconfirmed info, based only on users' experience and observations. JDM Legacy GT EJ20X and EJ20Y engines are also exceptions.''

===Subaru EL engine/Boxer type 3===
The '''({{langx|ja|[[:ja:スバル・EL15|Subaru EL engine]]}})''' replaced the EJ15 and is used in the JDM Subaru Impreza 1.5R (series GD, GG, GE, GH) starting with model year 2006. It is based on the EJ engine and shares many components, like the crankshaft from the EJ25. It has DOHC cylinder heads with AVCS variable valve timing on the intake.<ref>Subaru Technical Journal, No. 34 published in June 2007</ref><ref>Subaru Technical Journal, No. 33 issue published in June, 2006</ref>

*Displacement: 1,498&nbsp;cc
*bore x stroke: 77.7 x 79&nbsp;mm
*compression ratio: 10.1:1
*maximum horsepower: 110ps (81&nbsp;kW) at 6,400&nbsp;RPM
*maximum torque: 14.7kgm (144Nm) at 3,200&nbsp;rpm
*[[AVCS]]

=== [[Subaru EN engine]]===
The Subaru EN [[inline-four engine]] was introduced in 1988 to replace the [[Straight-twin engine|straight-two]] EK series engine that was originally engineered as an air-cooled engine, then modified as a water-cooled engine used in the 1969–1972 [[Subaru R-2]]. The EN was used in all [[kei cars]] and [[kei trucks]] in production by Subaru up until 2012.

===[[Subaru FA engine]]===
[[File:Subaru Levorg FA20 DIT engine at the Tokyo Motor Show 2013.jpg|thumb|Subaru FA20F]]
'''({{langx|ja|[[:ja:スバル・FA型エンジン|Subaru FA engine]]}})''' The FA was developed from the FB engine, however, efforts to reduce weight while maintaining durability were the main goals of the FA engine. While the FA and FB engines share a common platform, the FA shares very little in dedicated parts with the FB engine, with a different block, head, connecting rods, and pistons.<ref>{{cite web |url=http://www.autoweek.com/article/20111129/TOKYO/111129910 |title=Subaru shows production version of the BRZ |author=Mark Vaughn |publisher=Autoweek.com |access-date=2011-12-01 |archive-url=https://web.archive.org/web/20111203031801/http://www.autoweek.com/article/20111129/TOKYO/111129910 |archive-date=2011-12-03 |url-status=dead }}</ref>

*FA20D: 1,998&nbsp;cc [[Dual overhead camshaft|DOHC]], aka [[Toyota]] [[Toyota U engine#4U-GSE|4U-GSE]]; 2013-21 [[Toyota 86|Subaru BRZ/Toyota 86]]
*FA20F: 1,998&nbsp;cc [[Dual overhead camshaft|DOHC]], turbo, 2012+ JDM [[Subaru Legacy (fifth generation)#Legacy 2.0GT DIT|Subaru Legacy 2.0GT DIT]] and 2014+ [[Subaru Levorg]]; 2014+ USDM and JDM [[Subaru Forester]] XT; 2015-21 USDM [[Subaru WRX]]
*FA24D: 2,387&nbsp;cc [[Dual overhead camshaft|DOHC]], 2022+ [[Toyota 86|Subaru BRZ/Toyota 86]]
*FA24F: 2,387&nbsp;cc [[Dual overhead camshaft|DOHC]], turbo, 2019+ USDM [[Subaru Ascent]], 2020+ [[Subaru Legacy]], and 2020+ [[Subaru Outback]]. 2022+ USDM [[Subaru WRX]]

===[[Subaru FB engine]]===
[[File:Subaru 1.6 DIT engine.jpg|thumb|Subaru FB16F]]
The FB-series (initially available as naturally aspirated engines in 2.5- and 2.0-litre displacements) is the first new generation of boxer engine since the EJ-series. Subaru announced details of the FB engine on 23 September 2010.<ref>{{cite web |url=http://www.fhi.co.jp/english/contents/pdf_en_60853.pdf |title=FHI Develops a New-generation Subaru Boxer Engine |date=23 September 2010 |publisher=[[Fuji Heavy Industries]] |access-date=3 October 2010}}</ref> By increasing piston stroke and decreasing piston bore, Subaru aimed to reduce emissions and improve fuel economy, while increasing and broadening torque output over the previous generation engine.

The FB has an all-new block and head featuring dual overhead cams with intake and exhaust variable valve timing (AVCS - Active Valve Control System), and a timing chain that replaced the timing belt. Moving to chain-driven cams allows the valves to be placed at a more narrow angle to each other and shrinks the cylinder bore from 99.5&nbsp;mm to 94. It results in less unburned fuel during cold start, thereby reducing emissions. Subaru also uses asymmetrical connecting rods like those in '''EZ36'''. The FB is only marginally heavier and has similar exterior dimensions compared to an EJ engine of equivalent displacement. In Jan 2011, ''Car and Driver'' was told direct injection would be added soon.<ref name="car_and_driver_fb">{{cite web |url=http://www.caranddriver.com/news/subaru-fb-series-engine-subaru-flat-four-engines |title=Examining Subaru's New FB-series Flat-Four |last=Colwell |first=K.C. |date=January 2011 |work=[[Car and Driver]] |publisher=[[Hearst Corporation]] |access-date=15 April 2011}}</ref> Direct Injection was added to FB engines used in the 2017 Impreza, 2018 Crosstrek, 2019 Forester and the 2020 Legacy and Outback models.

Subaru claims a 28-percent reduction in friction losses, mainly due to lighter pistons and connecting rods.<ref name="car_and_driver_fb"/><ref>{{cite web |url=http://www.autocar.co.uk/CarReviews/FirstDrives/Subaru-Forester-2.0-XS/255245/ |title=Subaru Forester 2.0 XS review |last=Bremner |first=Richard |date=17 January 2011 |work=[[Autocar (magazine)|Autocar]] |publisher=[[Haymarket Media Group]] |access-date=15 April 2011}}</ref> The FB has a 10% improvement in fuel economy with the power coming on sooner and the torque band being broader.

* FB16E: 1600&nbsp;cc [[Double overhead camshaft|DOHC]], 2012+ EUDM [[Subaru XV|Subaru Impreza XV]] 1.6i
* FB16F: 1600&nbsp;cc [[Double overhead camshaft|DOHC]], turbo, 2014–20 [[Subaru Levorg]]
* FB20B: 1995&nbsp;cc [[Double overhead camshaft|DOHC]], 2011+ JDM [[Subaru Forester]], 2012-2016 [[Subaru Impreza]], and 2012-2017 [[Subaru XV]]
* FB20D: 1995&nbsp;cc [[Double overhead camshaft|DOHC]], 2018+ [[Subaru Impreza]], and 2018+ [[Subaru XV]]
* FB20X: 1995&nbsp;cc [[Double overhead camshaft|DOHC]], 2014–16 [[Subaru XV]] Hybrid
* FB20V: 1995&nbsp;cc [[Double overhead camshaft|DOHC]], 2019+ [[Subaru XV]] Hybrid
* FB25B: 2498&nbsp;cc [[Double overhead camshaft|DOHC]], 2011–18 North American [[Subaru Forester]], 2013-2019 North American [[Subaru Legacy]], and 2013-2019 North American [[Subaru Outback]]
* FB25D: 2498&nbsp;cc [[Double overhead camshaft|DOHC]], 2020+ North American [[Subaru Forester]], 2020+ North American [[Subaru Legacy]], 2020+ North American [[Subaru Outback]], and 2021+ North American [[Subaru XV]]

===[[Subaru CB engine]]===
{{expand-section|date=August 2020}}
The '''CB engine''' was first introduced in 2020 with the [[Subaru Levorg#2020|second-generation Levorg]].<ref>{{cite news |url=https://www.autoblog.com/2020/08/20/subaru-levorg-official-reveal-wrx-preview/ |title=Subaru Levorg, also known as the WRX's wagon cousin, revealed in production form |author=Stocksdale, Joel |date=August 20, 2020 |website=Autoblog |access-date=2 September 2020}}</ref><ref>{{cite news |url=https://paultan.org/2020/08/21/2020-subaru-levorg-officially-debuts-in-japan-sgp-platform-new-1-8l-turbo-boxer-engine-and-eyesight-x/ |title=2020 Subaru Levorg officially debuts in Japan – SGP platform; new 1.8L turbo boxer engine and EyeSight X |author=Lye, Gerard |date=August 21, 2020 |work=paultan.org |access-date=2 September 2020}}</ref> According to Subaru, CB stands for Concentration/Compact Boxer.<ref>{{cite news |url=https://car.watch.impress.co.jp/docs/news/1273449.html |title=スバル、新開発水平対向エンジン「CB18型」の疑問点を確認 「EJ20時代の強度剛性思想を採用」 |trans-title=Subaru answers questions about the newly developed boxer engine 'CB18': 'Adopts the strength and rigidity concept of the EJ20 era' |author=Tanikawa, Kiyoshi |date=August 28, 2020 |work=Car Watch |access-date=6 April 2021}}</ref> The first engine in the series is designated ''CB18'', a 1.8&nbsp;litre dual overhead cam 16-valve engine featuring dual [[active valve control system|AVCS]] with [[gasoline direct injection]] and a turbocharger. Bore and stroke are {{convert|80.6|×|88.0|mm|abbr=on}}, respectively, and the compression ratio is 10.4:1. Rated output power is {{convert|130|kW|PS hp|abbr=on}} at 5,200–5,600&nbsp;RPM and torque is {{convert|300|Nm|kgm lbft|abbr=on}} at 1,600–3,600&nbsp;RPM.<ref>{{cite web |url=https://www.subaru.jp/levorg/levorg/spec/spec.html |title=スペック |trans-title=Specifications |website=Subaru of Japan |access-date=2 September 2020}}</ref>

Compared to the FB16 used in the previous generation of the Levorg, the CB18 offers decreased fuel consumption ({{convert|16.6|km/L|mpgUS|abbr=on}} for the CB18 and {{convert|16.0|km/L|mpgUS|abbr=on}} for the FB16, both using the [[Fuel economy in automobiles#JC08|JC08 mode]]) and increased torque ({{convert|300|Nm|kgm lbft|abbr=on}} for the CB18 and {{convert|250|Nm|kgm lbft|abbr=on}} for the FB16). In addition, the CB16 achieves its peak torque at a lower engine speed. The CB18 also is shorter and lighter than the FB16; the bore pitch (centerline to centerline spacing between adjacent cylinders) has decreased from {{convert|113.0|to|98.6|mm|abbr=on}}, the overall crank length has decreased from {{convert|350.5|to|315.9|mm|abbr=on}}, and engine weight has been reduced by {{convert|14.6|kg|abbr=on}}.<ref name=Watch-20200827>{{cite news |url=https://car.watch.impress.co.jp/docs/news/1273157.html |title=スバル、新型レヴォーグのCB18エンジンは熱効率40％ λ＝2のリーン燃焼やオフセットシリンダー採用 |trans-title=Subaru's new Levorg CB18 engine uses lean combustion with a thermal efficiency of 40%, λ=2, and an offset cylinder |author=Tanikawa, Kiyoshi |date=August 27, 2020 |work=Car Watch |access-date=6 April 2021}}</ref> For the first time in a Subaru engine, the centerlines of the cylinder bores do not intersect with the crankshaft axis to reduce friction during the piston downstroke; instead, there is a crank offset of {{convert|8|mm|abbr=on}}. Overall [[thermal efficiency]] is 40% due to the adoption of [[lean-burn]] combustion with an [[Air–fuel ratio#Air–fuel equivalence ratio (λ)|excess air ratio (λ)]] of 2.<ref name=Watch-20200827/>

* CB18: 1795&nbsp;cc [[Double overhead camshaft|DOHC]], 2020 [[Subaru Levorg#2020|Subaru Levorg]], 2021 [[Subaru Forester#SK|Subaru Forester]]

==Six-cylinder==
{{main|Subaru six-cylinder engines}}
All of Subaru's six-cylinder engines are of a liquid-cooled, [[Flat-6]] [[Four-stroke engine|four-stroke]] design.

=== [[Subaru ER engine]] ===
'''({{langx|ja|[[:ja:スバル・EA型エンジン#ER27|Subaru ER27]]}})'''
Subaru introduced its first six-cylinder [[engine]] in its [[Subaru XT]] sports car.  This MPI [[SOHC]] 2-Valve engine was based on the EA82, with two cylinders added to the front.
* ER27: 2672&nbsp;cc [[SOHC]], 145&nbsp;hp at 5,200 rpm found in the 1987–1991 [[Subaru XT]]

=== Subaru EG engine ===
The '''({{langx|ja|[[:ja:スバル・EJエンジン#EG33|Subaru EG33]]}})''' engine was a direct replacement for the ER engine. The ER had been used only in the [[Subaru XT6]], which was being replaced by the [[Subaru Alcyone SVX]], and the company took the opportunity to create a new engine based on the more modern EJ rather than the EA engine series.  As the ER27 was to the EA82, Subaru took the EJ22 design and created a six-cylinder version to make the new EG33.  However, this four-valves-per-cylinder engine was [[Double overhead camshaft|DOHC]], and valvetrain parts came from the not yet released EJ25D.
Bore: 96.9 mm Stroke: 75 mm
* EG33: 3318&nbsp;cc [[Double overhead camshaft|DOHC]], 230&nbsp;hp at 5,400 rpm used in the 1992–1997 [[Subaru Alcyone SVX]]

===Subaru EZ engine===
[[File:SUBARU EZ36 001.jpg|thumb|right|Subaru EZ36]]
The '''({{langx|ja|[[:ja:スバル・EZエンジン|Subaru EZ series]]}})''' was introduced in 1999 in the Japanese market, in the [[Subaru Outback]], and in 2000 in the United States market, also in the Outback. It is a flat-six, 24-valve, quad-cam engine with an aluminium block and heads. It is available in EZ30 and EZ36 variants. Though the second iteration of the EZ30D used from 2003 to 2009 was heavily updated from the early EZ30D used from 2001 to 2003, Subaru continued to identify it as EZ30D. "EZ30R" is a false engine code often used on the Internet for the later EZ30, but Subaru has never used it as an official engine code.<ref>{{Cite web|url=https://parts.subaru.com/p/Subaru_2009_Outback30L-5ATLimited/ENGINE-ASSEMBLY/49222869/10100BR310.html|title=2009 Subaru Outback 3.0L 5AT Limited Engine assembly. Cooling - 10100BR310 - Genuine Subaru Part|website=parts.subaru.com}}</ref> All EZ-series engines use dual timing chains and feature coil-on-plug ignition.

{{anchor|EZ30D}}
The 2000-2003 EZ30D used one exhaust port per head, a cable-actuated throttle, variable intake geometry, and a cast aluminium intake manifold. It was only available with an automatic transmission.
*Displacement: 2999&nbsp;cc [[Double overhead camshaft|DOHC]]
*Bore: 89.2&nbsp;mm
*Stroke: 80&nbsp;mm
*Compression: 10.7:1
*Power: {{convert|220|PS|kW hp|0|abbr=on}} at 6000&nbsp;rpm
*Torque: {{convert|289|Nm|kg.m lbft|0|abbr=on}} at 4400&nbsp;rpm
*Application:
**2000–2004 [[Subaru Outback]] H6
**2002-2003 [[Subaru Legacy]] GT30
**2000–2003 [[Subaru Legacy]] Lancaster 6
**2002-2003 [[Subaru Legacy]] RS30<ref>{{cite web|last1=Reid|first1=Matt|title=Welcome to the Subaru Legacy Mini-Website|url=http://3keys-legacy.com/|website=3Keys Legacy|access-date=4 February 2018}}</ref>

The 2003-2007 EZ30D received new cylinder heads with 3 exhaust ports per head, [[Active valve lift system|AVLS]], [[Active valve control system|AVCS]] on the intake cams only, a drive-by-wire throttle, and a plastic intake manifold. It was available in manual and automatic unlike the original EZ30D.

*Displacement: 2999&nbsp;cc [[Double overhead camshaft|DOHC]]
*Bore: 89.2&nbsp;mm
*Stroke: 80&nbsp;mm
*Compression: 10.7:1
*Power: {{convert|180|kW|HP PS|abbr=on|}}@&nbsp;6,600&nbsp;RPM<ref name=3.0R-aus/><ref name=3.0R-frankfurt>{{cite press release |url=https://www.subaru.co.jp/en/news/archives/press/2003/03_08_08e.htm |title=Fuji Heavy Industries Will Unveil New Legacy and Outback at the 60th Frankfurt International Motor Show |date=August 8, 2003 |publisher=Fuji Heavy Industries, Ltd. |accessdate=25 April 2019}}</ref>
*Torque: {{convert|297|Nm|lbft|abbr=on|}}@&nbsp;4,200&nbsp;RPM<ref name=3.0R-aus>{{cite press release |url=http://subaru.com.au/news/?newsid=11894 |title=Outback 3.0R a new Subaru star |date=October 16, 2003 |publisher=Subaru of Australia |archive-url=https://web.archive.org/web/20040106133530/http://subaru.com.au/news/?newsid=11894 |archive-date=January 6, 2004 |url-status=dead}}</ref><ref name=Paris04>{{cite press release |url=https://www.subaru.co.jp/en/news/archives/press/2004/04_08_20e.htm |title=Exhibition outlines of the Mondial de l'Automobile 2004 (Paris Motor Show) |date=August 20, 2004 |publisher=Subaru Global Media |accessdate=23 July 2019}}</ref>
*Application:
**2003–2009 [[Subaru Legacy]] 3.0R
**2005–2009 [[Subaru Outback]] 3.0R
**2006–2007 [[Subaru Tribeca|Tribeca]]

{{anchor|EZ36D}}
The EZ36D retains the plastic intake manifold, 3 exhaust ports per head, and drive-by-wire throttle of the later EZ30D, but loses [[Active valve lift system|AVLS]] while gaining [[Active valve control system|AVCS]] for both intake and exhaust cams. The EZ36D also incorporates an asymmetrical connecting rod design shared with the FB series of engines and the EE20 diesel engine.

*Displacement: 3629&nbsp;cc [[Double overhead camshaft|DOHC]]
*Bore: 92&nbsp;mm
*Stroke: 91&nbsp;mm
*Compression: 10.5:1
*Power: {{convert|260|PS|kW hp|0|abbr=on}} at 6000&nbsp;rpm
*Torque: {{convert|350|Nm|kg.m lbft|0|abbr=on}} at 4400&nbsp;rpm
*Application:
**2010-2019 [[Subaru Legacy]]
**2010-2019 [[Subaru Outback]]
**2008-2014 [[Subaru Tribeca]]

==See also==
*[[AVCS|Subaru Active Valve Control System]]
*[[Active valve lift system|Subaru Active Valve Lift System]]
*[[Subaru 1235]]
*[[List of Subaru transmissions]]

==Notes==
{{reflist}}

==External links==
{{commons category|Subaru engines}}
* [http://www.subaru.com Subaru]

{{Subaru Corporation}}
{{Subaru}}

{{DEFAULTSORT:Subaru Engines}}
[[Category:Subaru engines| ]]
[[Category:Boxer engines]]
[[Category:Lists of automobile engines]]