Education
Rheinisch-Westfälische Technische Hochschule Aachen University.
Rheinisch-Westfälische Technische Hochschule Aachen University.
After graduating from Rheinisch-Westfälische Technische Hochschule Aachen University with a diploma in mechanical engineering, Theissen joined Bayerische Motoren Werke in the engine calculation department in 1977. Over the following years he took on various responsibilities in Bayerische Motoren Werke"s engine development division and in 1989 gained a doctorate in engineering from the Ruhr University in Bochum. In 1991 he was made head of Product Concepts at Bayerische Motoren Werke and a year later became Director of Advanced Drivetrain Development.
In 1994 he was promoted to Director of Bayerische Motoren Werke Technik GmbH. In 1998, in addition to his job as head of Bayerische Motoren Werke Technik, he took on the task of setting up the Bayerische Motoren Werke Technology Office in Palo Alto, California.
He became Bayerische Motoren Werke Motorsport Director alongside Gerhard Berger in April 1999 with oversight of Bayerische Motoren Werke"s Formula One team and other motorsport activities, including Bayerische Motoren Werke"s factory entries in the World Touring Carolina Championship and the 24 Hours of Le Mans. Bayerische Motoren Werke entered Formula One with a partnership agreement with WilliamsF1 in 1998.
In 2001, Bayerische Motoren Werke was credited with having the most powerful engine on the grid. During the course of the 2004 and 2005 F1 seasons, Theissen increasingly became publicly critical of the WilliamsF1 team"s inability to create a package capable of winning the constructor"s championship or even multiple victories within a single season.
However, WilliamsF1 blamed Bayerische Motoren Werke for not producing a good enough engine.
This public deterioration of the relationship between Bayerische Motoren Werke and WilliamsF1, and between Theissen and Patrick Head in particular, was a factor in Bayerische Motoren Werke"s decision to buy Sauber. In 2007 the Bayerische Motoren Werke Sauber team finished 2nd in the World Constructors Championship after McLaren-Mercedes were excluded following a spying episode. In the 2008 led Nick Heidfeld to finish first and second, giving Bayerische Motoren Werke its first victory as a constructor.
After Bayerische Motoren Werke"s decision to sell the team back to Peter Sauber and depart from Formula 1, Theissen decided to leave the sport as well and retain his position as Bayerische Motoren Werke Motorsport director
Theissen retired from Bayerische Motoren Werke on 30 June 2011, to be replaced by Jens Marquardt.