Editing Straight-three engine

{{Short description|Type of engine}}
[[File:Elsbett-3cyl-open.jpg|thumb|[[Engine block]] of an [[Elsbett]] straight-three diesel engine]]
A '''straight-three engine''' (also called an '''inline-triple''' or '''inline-three''')<ref name="Saab96nV4Robson">{{cite book |last = Robson |first = Graham |title = Saab 96 & V4 |series = Rally Giants |date = August 15, 2010 |publisher = Veloce Publishing |isbn = 978-1-84584-256-7 |page = 27 |chapter = The car and the team |quote = V4 replaces straight three}}</ref><ref>{{cite journal |last1 = Gorant |first1 = Jim |editor-last = Oldham |editor-first = Joe |date=December 1997 |title = Jet Ski Saviors |journal = [[Popular Mechanics]] |volume = 174 |issue = 12 | pages = 54–57 |location = New York, NY USA |publisher = Hearst |issn = 0032-4558 |access-date = 2012-07-02 |url = https://books.google.com/books?id=MGYEAAAAMBAJ&q=Inline+Triple+Popular+Mechanics |quote = The 1071cc, inline, triple-cylinder configuration produces 803 pounds of thrust and pushes the boat to about 55&nbsp;mph.}}</ref><ref name="RnT3x3July93">{{cite journal |editor-last = Dinkel |editor-first = John |date=July 1988 |title = Comparison Road Test: 3x3 |journal = [[Road & Track]] |volume = 39 |issue = 11 |pages = 66–74 |location = Newport Beach, CA USA |publisher = Diamandis Communications |issn = 0035-7189 |quote = Its engine is still the same 993-cc sohc inline-3, producing 48&nbsp;bhp at 5100&nbsp;5100 rpm and 57&nbsp;lb-ft torque at 3200...}}</ref> is a three-cylinder [[reciprocating engine|piston engine]] where cylinders are arranged in a line along a common crankshaft.

Less common than [[straight-four engine]], straight-three engines have nonetheless been used in various motorcycles, cars and agricultural machinery.

== Design ==
[[File:Reihenmotor Drei Zylinder.gif|thumb|four stroke Straight-three engine with firing order 1-3-2]]
A [[crankshaft]] angle of 120 degrees is typically used by straight-three engines,<ref>{{Cite web|url=https://www.carthrottle.com/post/heres-the-problem-with-three-cylinder-engines/|title=Here's The Problem With Three-Cylinder Engines|website=Car Throttle|language=en|access-date=2019-12-03}}</ref> since this results in an evenly spaced [[Firing order#Firing interval|firing interval]]. Another benefit of this configuration is perfect [[Engine balance#Primary balance|primary balance]] and [[Engine balance#Secondary balance|secondary balance]], however an end-to-end [[Couple (mechanics)|rocking couple]] is induced because there is no symmetry in the piston velocities about the middle piston. A [[balance shaft]] is sometimes used to reduce the vibrations caused by the rocking couple.

Other crankshaft angles have been used occasionally. The 1976–1981 [[Laverda Jota]] motorcycle used a 180 degree crankshaft, where the outer pistons rise and fall together and inner cylinder is offset from them by 180 degrees. This results in three power strokes evenly-spaced at 180 degrees each, and then no power strokes during the final 180 degrees of crankshaft rotation. The 2020 [[Triumph Tiger 900 (2020)|Triumph Tiger 900]] motorcycle uses a "T-Plane" crankshaft where the crankshaft throws are at 90 intervals, such that the throws for cylinders 1 and 3 are separated by 180 degrees (therefore the three throws together forming a "T" shape when viewed from the end).<ref>{{cite web |title=TIGER 900 ENGINE & CAPABILITY |url=https://www.triumphmotorcycles.co.uk/motorcycles/adventure/tiger-900/engine-and-capability |website=Triumph Motorcycles UK |access-date=10 February 2020}}</ref><ref>{{cite web |last1=Cameron |first1=Kevin |title=Triumph's New T-Plane Firing Order Explained |url=https://www.cycleworld.com/story/bikes/triumphs-new-t-plane-firing-order-explained/ |website=Cycleworld |access-date=10 February 2020}}</ref>

== Usage in cars ==
[[File:Tuned-SAAB-twostroke.jpg|thumb|Circa-1960 [[Saab two-stroke]] engine]]
[[File:Suzuki K10B.JPG|thumb|2010 [[List of Suzuki engines#K engine|Suzuki K10B]] engine]]

Among the first cars to use a straight-three engine is the 1953–1955 [[DKW#Automobiles made after 1945|DKW F91]], powered by a {{convert|900|cc|cuin|0|abbr=on}} [[two-stroke engine]], although this was predated by the 3 cylinder 15hp Rolls Royce produced in 1905 and a number of other cars of this era also used 3 cylinder engines.  The 1956–1960 [[Saab 93]] saw the introduction of Saab's {{convert|750|cc|cuin|0|abbr=on}} two-stroke engine, which was also used in the [[Saab 95]], [[Saab 96]] and [[Saab Sonett]] until 1968 after which it was replaced by the [[Ford Taunus V4 engine]].

The [[Wartburg (car)|Wartburg]] cars (manufactured in East Germany) and [[FSO Syrena]] (manufactured in Poland) also used straight-three engines.

The 1967 [[Suzuki Fronte#Fronte 360|Suzuki Fronte 360]] uses a {{convert|256|cc|0|abbr=on}} two-stroke engine. In 1980, Suzuki began production of a {{convert|543|cc|0|abbr=on}} four-stroke engine, which was introduced in the Alto and Fronte models.

The [[Subaru EF engine]] is a 4-stroke petrol engine which was introduced in 1984 and used in the [[Subaru Justy|Justy]]<ref name="RnT3x3July93" /> and the [[Subaru Sumo|Sumo]] (the export version of the Sambar).

The straight-three versions of the [[Ford EcoBoost engine]] – a turbocharged 1.0-litre petrol engine – was introduced in the 2012 Ford Focus.<ref>{{cite web |url=https://social.ford.com/en_US/story/sustainability/green/smallest-ford-engine-ever-three-cylinder-ecoboost-and-two-new-transmissions.html |title=Smallest Ford Engine Ever! Three-Cylinder EcoBoost (and Two New Transmissions) |access-date=2017-04-03}}</ref> It uses an unbalanced flywheel to shift the inherent three-cylinder imbalance to the horizontal plane where it is more easily managed by engine mounts, and so remove the need to use balance shafts.<ref>{{cite web|url=http://wardsauto.com/technology/ford-s-3-cyl-ecoboost-delivers-goods |title=Ford's 3-cyl. EcoBoost Delivers the Goods |date=2014-05-15 |access-date=2017-04-03}}</ref> In 2016, [[cylinder deactivation]] was added, claimed to be a world first for three-cylinder engines.<ref>{{cite web|url=https://media.ford.com/content/fordmedia/feu/en/news/2016/11/29/ford-to-offer-fuel-saving-cylinder-deactivation-tech-for-1-0-lit.html |title=Ford To Offer Fuel-Saving Cylinder Deactivation Tech FOR 1.0 Litre EcoBoost; Global First For A 3-Cylinder Engine |date=2016-11-29 |access-date=2017-04-03}}</ref>

{| class="wikitable sortable"
|+ Other car engines
|-
! Years !! Name !! Fuel!! Notes
|-
| 1977–1993 || [[Daihatsu C-series engine|Daihatsu C-series]] || Petrol || Used in the [[Daihatsu Charade#First generation (G10, G20; 1977–1983)|Daihatsu Charade]] and [[Daihatsu Mira#L70/L80 series (1985)|Daihatsu Mira/Cuore]]<ref>{{cite web | url = http://motormania.eu.com/MM/2011/09/23/car-2012-daihatsu-mira-es/ | title = New car: 2012 Daihatsu Mira e:S | author = Logan | date = September 23, 2011 | work = Motor Mania | access-date = 2012-07-03 | quote = Motivation comes from a 3-cylinder, 650cc petrol engine that kicks out a mere 51bhp (52PS/38kW) and 60Nm (44lb-ft) of torque.}}</ref>
|-
| 1983–2001 || [[Suzuki G engine#G10|Suzuki G10]] || Petrol || Debuted in the [[Suzuki Cultus|Suzuki Cultus/Swift]]<ref name="RnT3x3July93" /><ref>{{cite web|author=Daniel Zevedei |url=http://www.auto-types.com/suzuki-swift-10-gl-5-doors-hatchback-5-speed-manual-63979.html |title=Suzuki Swift 1.0 GL - 5-doors, hatchback |publisher=Auto-types.com |access-date=2014-06-20}}</ref>
|-
| 1986–1995 || [[List of VM Motori engines#R392|VM Motori R392]] || Diesel || Turbocharged, used in the [[Alfa Romeo 33]]
|-
| 1987–present || [[Mitsubishi 3G8 engine|Mitsubishi 3G8]] || Petrol || Debuted in the [[Mitsubishi Minica]]
|-
| 1991–1992 || Elsbett ELKO 3.82.92t || Diesel || Small-scale production engine for biodiesel conversions 
|-
| 1991–2008 || [[Daewoo S-TEC engine#S-TEC|Daewoo S-TEC]] || Petrol || Used in the [[Daewoo Tico]] and [[Daewoo Matiz]]
|-
| 1996–2002 || [[GM Family 0 engine#Generation I|GM X10XE]] || Petrol || Debuted in the [[Opel Corsa#Corsa B (S93; 1993)|Opel Corsa]]
|-
| 1998–2007 || [[Mercedes-Benz M160 engine|Mercedes-Benz M160]] || Petrol || Turbocharged, used by [[Smart (marque)|Smart]]
|-
| 1998–2005 || [[List of discontinued Volkswagen Group diesel engines#1.2 R3 PD TDI 3L|Volkswagen R3 PD TDI 3L]] || Diesel || Turbocharged, used in the [[Volkswagen Lupo#Lupo 3L|Volkswagen Lupo]] and [[Audi A2#1.2 TDI "3L"|Audi A2]]<ref>{{cite press release|title=Audi A2 1.2 TDI: the three-litre car from Audi|url=http://www.audiworld.com/news/99/a2_2/content.shtml|date=1999-11-28|work=AUDI AG - press release|publisher=AudiWorld.com|access-date=2009-08-22}}</ref>
|-
| 1999–2014 || [[Mercedes-Benz OM660 engine|Mercedes-Benz OM660]] || Diesel || Turbocharged, used by [[Smart (marque)|Smart]] 
|-
| 1999–2005 || [[List_of_VM_Motori_engines#R_315_SOHC|VM Motori R 315]] || Diesel || Turbocharged, debuted in the [[Hyundai_Accent#Second_generation_(LC;_1999)|Hyundai Accent]]
|-
| 2000–2006 || [[Honda_E0_engine#ECA1|Honda ECA1]] || Petrol || Used by the [[Honda_Insight#First generation (ZE1; 1999)|Honda Insight]] hybrid car
|-
| 2003–present || [[Mitsubishi 3A9 engine|Mitsubishi 3A9]] || Petrol || Debuted in the [[Mitsubishi_Mirage#Sixth_generation_(A00/LA,_A10;_2012)|Mitsubishi Mirage]]<ref name="LittleSmartBook">{{cite book| last = Jackson| first = Paul| title = The Little Book of Smart| date = February 1, 2008| publisher = Veloce Publishing| isbn = 978-1-84584-148-5| pages = 94–95| chapter = Chapter 6: The Next Generation| quote = There were plenty of changes under the skin, too, with the original smart-built turbocharged engine being replaced (on petrol-engined versions) by a Mitsubishi design – still with three cylinders but now a larger (999cc) capacity.}}</ref>
|-
| 2004–2011 || [[Hyundai_U_engine#1.1_L_(D3FA)|Hyundai U engine]] || Diesel || Turbocharged, debuted in the [[Kia_Picanto#First generation (SA; 2003)|Kia Picanto]]
|-
| 2004–present || [[List_of_Volkswagen_Group_petrol_engines#1.2_R3_(EA111)|Volkswagen R3 (EA111)]] || Petrol || Debuted in the [[Volkswagen_Fox#Europe|Volkswagen Fox]]<ref>{{cite web|title=New VW Fox in depth|url=http://www.worldcarfans.com/10504049256/6|work=Volkswagen AG|publisher=WorldCarFans.com|date=2005-04-04|access-date=2009-08-18}}</ref>
|-
| 2004–2009 || [[Mercedes-Benz OM639 engine|Mercedes-Benz OM639]] || Diesel || Turbocharged, used by the [[Smart_Forfour#First_generation_(W454;_2004–2006)|Smart Forfour]] and [[Mitsubishi_Colt#Colt_(Z30;_2002)|Mitsubishi Colt]]<ref>{{cite web|author=Daniel Zevedei |url=http://www.auto-types.com/mitsubishi-colt-11-inform-5-doors-hatchback-5-speed-manual-40988.html |title=Mitsubishi Colt 1.1 Inform - 5-doors, hatchback |publisher=Auto-types.com |access-date=2014-06-20}}</ref><ref>{{Cite web|title=Om639 Engine - Diesel Engine - Turbocharger|url=https://www.scribd.com/document/356042267/Om639-Engine|access-date=2020-08-24|website=Scribd|language=en}}</ref>
|-
| 2004–present || [[Toyota_KR_engine#1KR-FE|Toyota 1KR-FE]] || Petrol || Debuted in the [[Toyota_Aygo#First_generation_(AB10;_2005)|Toyota Aygo]]
|-
| 2010–present || [[Nissan HR engine|Nissan HR]] || Petrol || Some versions supercharged, debuted in the [[Nissan_Micra#Fourth_generation_(K13;_2010)|Nissan Micra]]<ref>{{cite web|url=http://www.nissan-global.com/EN/TECHNOLOGY/OVERVIEW/hr12ddr.html |title=HR12DDR Engine &#124; NISSAN &#124; TECHNOLOGICAL DEVELOPMENT ACTIVITIES |publisher=Nissan-global.com |access-date=2014-06-20}}</ref>
|-
| 2011–2017 || [[Fiat_JTD_engine#1.0|Fiat XSDE]] || Diesel || Debuted in the India-market [[Chevrolet_Spark#M300|Chevrolet Beat]]<ref>{{cite journal|url=http://www.bsmotoring.com/news/launched-chevrolet-beat-diesel-starts-at-rs-429-lakh/3813/1|title=LAUNCHED! Chevrolet Beat diesel starts at Rs 4.29 lakh|website=WWW.bsmotoring.com|publisher=BS Motoring|date=July 25, 2011}}</ref>
|-
| 2012–present
| [[Ford Motor Company|Ford]] [[Ford EcoBoost engine|EcoBoost]]
| Petrol
| Some versions turbocharged, debuted in the [[Ford Focus (third generation)|Ford Focus (3rd generation)]]
|-
| 2012–present || [[BMW B37]] || Diesel || Turbocharged, debuted in the [[Mini_Hatch#Third_generation_(F55/56/57;_2013)|Mini (F56)]]
|-
| 2012–present || [[List of Renault engines#H|Renault TCe]] || Petrol ||Naturally aspirated and  Turbocharged, debuted in the [[Renault_Clio#Clio_IV_(2012)|Renault Clio IV]]{{Broken anchor|date=2024-06-03|bot=User:Cewbot/log/20201008/configuration|target_link=Renault_Clio#Clio IV (2012)|reason= The anchor (Clio IV (2012)) [[Special:Diff/991154278|has been deleted]].}}
|-
| 2013–present || [[BMW B38]] || Petrol || Turbocharged, debuted in the [[BMW i8]]
|-
| 2013–present || [[GM small gasoline engine]] || Petrol || Turbocharged, debuted in the [[Opel Adam]]<ref>{{cite web|url=http://media.opel.com/content/media/intl/en/opel/news.detail.html/content/Pages/news/intl/en/2013/opel/08-07-newall-aluminium-3-zylinder-turbo.html |title=New All-Aluminum 3-Cylinder Turbo Sets Refinement Benchmark |publisher=Media.opel.com |date=2013-08-07 |access-date=2014-06-20}}</ref><ref>{{cite web|url=http://media.gm.com/media/intl/en/opel/news.detail.html/content/Pages/news/intl/en/2013/opel/10-08-opel-sidi-turbo-aachen.html |title=Opel presents new 1.0 ECOTEC Direct Injection Turbo engine at Aachen Colloquium |publisher=Media.gm.com |date=2013-10-08 |access-date=2014-06-20}}</ref>
|-
| 2014–present || [[List_of_PSA_engines#EB|PSA Group PureTech]] || Petrol ||Naturally aspirated and Turbocharged, debuted in the [[Peugeot_308#Second generation (T9; 2013)|Peugeot 308]]
|-
| 2018–present || [[GM E-Turbo engine|GM E-Turbo]] || Petrol || Turbocharged; debuted in the [[Chevrolet Orlando#Second generation (2018)|Chevrolet Orlando]]
|-
| 2020–present || [[Toyota]] [[Toyota G16E engine|G16E]] || Petrol || Turbocharged, debuted in the [[Toyota GR Yaris]]
|-
| 2020-present || [[Koenigsegg]] [[Koenigsegg TFG|TFG]] engine || Petrol || Turbocharged, Freevalve engine debuted in [[Koenigsegg Gemera]].
|-
|2016-present
|[[Fiat Chrysler Automobiles|FCA]] [[Fiat Global Small Engine]] "FireFly"
|Petrol
|Naturally aspirated and Turbocharged, debuted in the Brazilian version of the 2017 [[Fiat Uno#Fiat Novo Uno (2010–2021)]]
|}

== Usage in motorcycles ==
[[File:Kawasaki H1 Mach III 500cc.jpg|thumb|right|1969–1975 [[Kawasaki H1 Mach III]] ]]
[[File:Triumph Rocket III engine.jpg|thumb|right|2004–present [[Triumph Rocket III]] engine ]]

{{See also|List_of_motorcycles_by_type_of_engine#Straight_three {{!}} List of motorcycles by type of engine}}

The advantages of a straight-three engine for motorcycles are that it has a shorter length than an inline-four engine and produces less vibration than a straight-twin engine.<ref>How Your Motorcycle Works: Your Guide to the Components & Systems of Modern Motorcycles. Peter Henshaw Veloce Publishing Ltd, 15 Sep 2012</ref>{{page needed|date=November 2020}}

===Four-stroke===
[[Four-stroke]] straight-three engines have been used in road bikes and racing bikes by several companies.<ref name=ride>365 Motorcycles You Must Ride. Dain Gingerelli, Charles Everitt, James Manning Michels. MBI Publishing Company, 10 Jan 2011</ref>{{page needed|date=November 2020}}<ref>The Motorcycle Book, Alan Seeley. MotorBooks International, 2 May 2004</ref>{{page needed|date=November 2020}}<ref>Human Hurricane, Wilson, Steve. Walneck's Classic Cycle Trader, April 2005</ref>{{page needed|date=November 2020}} 

From 1985–1995, the [[BMW_K100#K75|BMW K75]] was produced with a straight-three engine (based on the straight-four engine from the BMW K100).

British company [[Triumph Motorcycles Ltd|Triumph]] is particularly renowned for a transversely-mounted straight-three engine. Variants have been used in their [[Triumph Speed Triple|Speed Triple]],<ref>Cycle world, Volume 44 CBS Publications, 2005. "inline triple"</ref> [[Triumph Trident|Trident]], [[Triumph Sprint (disambiguation)|Sprint]], and [[Triumph Tiger|Tiger]] series.
In addition Triumph makes the [[Triumph Rocket III|Rocket III]] model, various variants of which have held the record for motorcycle with the largest engine displacement.<ref>Triumph Motorcycles: Twins & Triples. Timothy Remus. MotorBooks International, 10 Oct 1997</ref> <!-- not sure, but it looks like a longitudinal inline. Therefore split off the sentence. -->

In [[2019 Moto2 season|2019]], the Moto2 class in the [[Grand Prix motorcycle racing|MotoGP World Championship]] switched to using Triumph 765 cc (46.7 cu in) triple engines.<ref name="Telegraph 2019">[https://www.telegraph.co.uk/cars/features/triumph-enters-grand-prix-racing-moto2-engine-supplier/ Triumph enters Grand Prix racing as Moto2 engine supplier] ''[[The Daily Telegraph|The Telegraph]]'', 18 December 2018. Retrieved 15 December 2019.</ref>

===Two-stroke===
[[Two-stroke engine|Two-stroke]] designs are less common in straight-three engines than four-stroke designs, however several were produced by Japanese manufacturers in the late 1960s through to 1980s. 

The [[Kawasaki triple]] engine was produced from 1968 to 1980 and was used in various road bikes and racing bikes.<ref>The Kawasaki Triples Bible: All Road Models 1968–1980, Plus H1r and H2r Racers in Profile. Alastair Walker, Veloce Publishing Ltd, 15 Jan 2011. P.18</ref><ref>365 Motorcycles You Must Ride. Dain Gingerelli, Charles Everitt, James Manning Michels. MBI Publishing Company, 10 Jan 2011. P.188</ref> Most versions were air-cooled, however several were water-cooled.<ref name="walker">Japanese Production Racing Motorcycles. Mick Walker. Redline Books, Sep 2004</ref> Similarly, the 1972–1980 [[Suzuki GT series]] engines were used for both road bike and racing bikes, and were available in both air-cooled and water-cooled versions.<ref name="walker" />
{{clear right}}

== Other uses ==
=== Agriculture ===
[[File:FairbanksMorse-EngPump-JSPark-Aug2008.jpg|thumb|1940s [[Fairbanks-Morse]] straight-three diesel engine]]

An example of an agricultural application is the ''[[Fairbanks-Morse]] 32E14'' low-speed diesel engine.

The straight-three layout is common for diesel [[tractor]] engines, such as the ''[[Perkins Engines|Perkins]] AD3.152''. This engine was used in the [[Massey Ferguson 35]] and [[Fordson]] Dextra tractors, as well as for marine and stationary applications.

=== Aviation ===
The [[Hewland AE75]] is a 750&nbsp;cc two-stroke aircraft engine that was produced in the mid-1980s. It was an inverted three-cylinder design with liquid-cooling that produced {{convert|75|bhp|abbr=on}}.<ref>“Pilot” magazine February 1986 page 32</ref>
{{clear right}}

== See also ==
{{commons category|Straight-3 engines}}
* [[Straight engine]]
* [[V3 engine]]
{{clear right}}

== References ==
{{reflist|30em}}

{{piston engine configurations}}

{{DEFAULTSORT:Straight-03}}
[[Category:Straight engines|3]]
[[Category:Straight-three engines| ]]