Editing Detroit Diesel (section)

===Shift to four-cycle engines and spinoff===
* 1980: Detroit Diesel-Allison produced its first four-cycle engine. A few years later in the early 1980s diesel engine production split off as Detroit Diesel Division while turbine engines remained as Allison Division.
* 1987: [[Detroit Diesel 60|The Series 60]] — the four-cycle heavy-duty engine for which the company is well known — was introduced. It was the first production engine to have integrated electronic controls as a standard feature. The Series 60 was cleaner and more fuel-efficient than previous heavy-duty engines, and became the biggest selling heavy-duty diesel engine in the North American Class 8 truck market.
* 1988 January 1: A joint venture between [[Penske Corporation]] and General Motors created Detroit Diesel Corporation. Penske had a 60% majority ownership in the new venture and the CEO was former racecar driver [[Roger Penske]].<ref>{{cite news|last=Levin|first=Doron|url=https://www.nytimes.com/1989/05/25/business/penske-wins-big-at-detroit-diesel.html|title=Penske Wins Big at Detroit Diesel|newspaper=[[The New York Times]]|date=May 25, 1989|access-date=October 3, 2013}}</ref><ref>{{cite web|url=http://www.motortrend.com/features/112_0508_roger_penske/viewall.html|title=People: Roger Penske...This Guy Should Run GM|work=[[Motor Trend]]|access-date=October 3, 2013|archive-date=October 5, 2013|archive-url=https://web.archive.org/web/20131005033634/http://www.motortrend.com/features/112_0508_roger_penske/viewall.html|url-status=dead}}</ref><ref>{{cite magazine |url=https://books.google.com/books?id=NInY5GUWdX0C&pg=RA3-PA55 |title=The Penske Philosophy |date=July–August 1988 |magazine=Boating |pages=55–62 |access-date=12 June 2024}}</ref>
* 1993 October: Detroit Diesel Corporation had grown its on-highway heavy-duty market share to 33% from 3% only a few years earlier. The company also made an [[initial public offering]] of common stock, becoming a publicly traded company listed on the [[New York Stock Exchange]] under the stock symbol "DDC". That same year, Detroit Diesel launched the Series 50, the first Detroit Diesel natural gas engine.
* 1999: Detroit Diesel built its 4 millionth engine.