Wilksch Airmotive Ltd is a UK-based company which designs and manufactures compression-ignition engines for light aircraft. Wilksch engines run on jet fuel, which is cheaper and more widely available than avgas. The company, founded in 1994, manufactures two-stroke compression ignition engines. In a maiden flight in a Piper J-3 Cub on 21 November 1997, an 80-horsepower 2-cylinder prototype engine became the first two-stroke diesel aircraft engine to fly in over 50 years.
The company then concentrated on developing a three-cylinder 120 hp WAM engine, which first flew in December 1999. In 2005 the Wilksch company announced a manufacturing deal with Lister Petter — effectively the WAM (Wilksch Air Motive) company would lease space, but would actually manufacture at the Lister Petter factory in Gloucestershire, UK. In the following 18 months some 40 engines were made; to date[when?] it is believed that about 20 have flown in kit built aircraft in places as far apart as Brazil, the United States, Sweden, Germany, France and the UK.
In 2006 the company faced financial difficulties — not uncommon with such high tech/high design demand scenarios.
Wilksch Airmotive moved into premises at Gloucestershire Airport at the end of 2007 where they are continuing to develop their diesel engines. They have test cells in which they run the engines to JAR cycles. WAM moved to a low volume production regime of the existing design and returned to development with the aim of creating the next generation of engines, namely a larger capacity version of the three-cylinder engine and (in due course) a four-cylinder version.
In 2005 Wilksch  reduced his equity stake in Wilksch Airmotive, handing control to an investor group including Mike Newton, the new CEO. In 2007 Wilksch left the company to work with Continental Motors, Inc. in the United States. He then established an Anglo-Australian consultancy company, "Wilksch Aero". 
In July 2009 Liberty Aerospace unveiled a version of their XL2 two-seat aircraft powered by a Wilksch turbo-diesel engine, aimed at the non-North American market. Liberty Aerospace is assisting Wilksch in certifying this engine. The XL2 is usually powered by a Continental IOF-240-B, but a WAM variant which burns Jet A fuel would appeal to overseas markets where avgas is expensive or unobtainable. Should Liberty offer the WAM engine as a factory-fitted option for the XL2, this will be a major boost that may help secure the future of Wilksch Airmotive.
Since the beginning of the 2008 global recession, sales of the XL2 have been very slow, and in 2011 the company shipped only two aircraft; but in late September 2012 the sale of 50 XL2s to the city of Wuhan, China was announced. In October 2012 the Chinese order was increased to 200 aircraft, with components being shipped to Wuhan for final assembly. Chinese interests may also purchase a part-ownership in the company.
- Liberty Aerospace (July 2009). "Liberty Enters into Agreement with Wilksch Airmotive for Testing and Certification of the WAM Turbo Diesel Engine". Retrieved 2009-09-15.
- Pew, Glenn (28 September 2012). "China Saves Liberty". AVweb. Retrieved 1 October 2012.
- Light Aircraft Association (5 October 2012). "News Update". Retrieved 6 October 2012.
- www.wilksch.com — Wilksch Airmotive Ltd. site
- http://www.libertyaircraft.com/airplane-news-center/libertyentersintoagreementwithwilkschairmotivefortestingandcertificationofthewamturbodieselengine.php Liberty XL2 powered by Wilksch