Editing Wankel engine (section)

===As a vehicle range extender===
[[File:Hybridpeak.svg|thumb|'''Figure 24.'''<br/>Structure of a series-hybrid vehicle. The grey square represents a differential gear. An alternative arrangement (not shown) is to have electric motors at two or four wheels.]]

Due to the compact size and the high [[power-to-weight ratio]] of a Wankel engine, it has been proposed for electric vehicles as [[range extender]]s to provide supplementary power when electric battery levels are low. A Wankel engine used as a generator has packaging, noise, vibration, and harshness advantages when used in a passenger car, maximizing interior passenger and luggage space, as well as providing a good noise and vibration emissions profile. However, it is questionable whether or not the inherent disadvantages of the Wankel engine allow the usage of the Wankel engine as a range extender for passenger cars.<ref name="Merker Teichmann Springer Fachmedien Wiesbaden 2019 p. 484">{{cite book |last1=Merker |first1=Günter P. |last2=Teichmann |first2=Rüdiger |author3=Springer Fachmedien Wiesbaden |title=Grundlagen Verbrennungsmotoren Funktionsweise und alternative Antriebssysteme Verbrennung, Messtechnik und Simulation |place=Wiesbaden, Germany |date=2019 |isbn=978-3-658-23556-7 |oclc=1062240250 |language=de |page=484}}</ref>

In 2010, [[Audi]] unveiled a prototype series-hybrid electric car, the [[Audi A1#A1 e-tron|A1 e-tron]]. It incorporated a Wankel engine with a chamber volume V<sub>k</sub> of 254&nbsp;cm<sup>3</sup>, capable of producing 18&nbsp;kW at 5000 rpm. It was mated to an electric generator, which recharged the car's batteries as needed and provided electricity directly to the electric driving motor. The package had a mass of 70&nbsp;kg and could produce 15&nbsp;kW of electric power.<ref name="Ribau Silva Brito Martins 2012 pp. 120–133">{{cite journal |last1=Ribau |first1=João |last2=Silva |first2=Carla |last3=Brito |first3=Francisco P. |last4=Martins |first4=Jorge |title=Analysis of four-stroke, Wankel, and microturbine based range extenders for electric vehicles |journal=Energy Conversion and Management |publisher=Elsevier BV |volume=58 |year=2012 |issn=0196-8904 |doi=10.1016/j.enconman.2012.01.011 |pages=120–133|bibcode=2012ECM....58..120R }}</ref>

[[File:DEMIO EV 20130126-1.JPG|thumb|'''Figure 25.'''<br/>Mazda2 EV prototype]]

In November 2013, Mazda announced to the motoring press a series-hybrid prototype car, the [[Mazda Demio|Mazda2 EV]], using a Wankel engine as a range extender. The generator engine, located under the rear luggage floor, is a tiny, almost inaudible, single-rotor 330-cc unit, generating {{cvt|30|hp|order=flip}} at 4,500{{nbsp}}rpm and maintaining a continuous electric output of 20&nbsp;kW.<ref>{{cite magazine|first1=Owen |last1=Mildenhall |url= http://www.autoexpress.co.uk/mazda/2/84660/mazda-2-ev-gets-new-rotary-range-extender-engine |title=Mazda 2 EV gets new rotary range extender engine |magazine=Auto Express |date=2013-11-25 |access-date=2014-02-01}}</ref><ref>{{cite web |first1=Toby |last1=Hagon |url= http://news.drive.com.au/drive/new-car-reviews/mazda2-ev-range-extender-first-drive-review-20131125-2y4p3.html |title=Mazda2 EV range extender first drive review |website=[[Drive.com.au]]|date=2012-02-21 |access-date=2014-02-01 |archive-url= https://web.archive.org/web/20131203003056/http://news.drive.com.au/drive/new-car-reviews/mazda2-ev-range-extender-first-drive-review-20131125-2y4p3.html |archive-date=2013-12-03 |url-status=dead}}</ref><ref name="Xr2Bg">{{cite web|last1=Ingram |first1=Antony |url= http://www.greencarreports.com/news/1088728_rotary-engine-lives-on-in-range-extended-electric-mazda-2-prototype |title=Rotary Engine Lives On In Range-Extended Electric Mazda 2 Prototype |website=greencarreports.com |date=26 November 2013 |access-date=2014-02-01}}</ref>

Mazda introduced the [[Mazda MX-30|MX-30 R-EV]] fitted with a Wankel engine range extender in March 2023.<ref name="capomazda.com"/> The car's Wankel engine is a naturally aspirated single-rotor unit with a chamber volume V<sub>k</sub> of {{cvt|830|cm3|in3|1}}, a compression of 11.9, and a rated power output of {{cvt|55|kW|hp|0}}. It has [[petrol direct injection]], [[exhaust gas recirculation]], and an exhaust-gas treatment system with a [[Three-way catalyst|TWC]] and a [[Diesel particulate filter|particulate filter]]. According to ''[[auto motor und sport]]'', the engine is Euro 6d-ISC-FCM-compliant.<ref name="auto motor und sport 2023"/><ref name="auto1"/>