From Chateauroux, Tetu studied at the Ecole Superieure des Techniques Aeronautiques et de Construction Automobile (ESTACA) before joining Charles Deutsch's Automobiles CD in 1965 as a designer of the company's sportscars which enjoyed minor success at the Le Mans 24 Hours. This led to Tetu being hired in 1969 by Guy Ligier. His job was to design the Ligier JS1 sportscar. The cars were fitted with Cosworth engines and were both raced and sold to the public. The Ford engines were later replaced by Maseratis and the cars - and its successors - did well. As a result Tetu was recruited by Alfa Romeo in 1972 to work on its T33 sportscar program. This resulted in victory for the company in the World Championship of Makes in 1975.The following year Tetu left Milan and returned to France to work on the Renault rally program but in 1978 he was recruited to be chief designer for the Renault Sport F1 team. His first car was the Renault RS10 which were driven with some success in 1979 by Jean-Pierre Jabouille and Rene Arnoux. The RE20 and RE30 models which followed in 1981 and 1982 were very successful in the hands of Arnoux and Alain Prost although the team missed out on the World Championship in 1983. The 1984 season - with the RE50 chassis - was not a success and neither Patrick Tambay nor Derek Warwick were able to win with the car. At the end of the year Tetu moved to Ligier to become chief designer. He developed the Ligier-Renault JS25 and then designed its replacement - the JS27 - and the team was able to finish fifth in the World Championship in 1986.Ligier ran into trouble with engines in 1987. A planned relationship with Alfa Romeo ended quickly and the JS29, which had been designed for the Italian engines, ended up being fitted with Megatron turbos. There were several redesigns but results were few and far between. For the 1988 season Tetu took a risk. The team had Judd engines and, in an effort to reduce drag, Tetu came up with the idea of putting the fuel tanks around the driver and between the chassis and the engine. The result was a very low sleek car - but it handled terribly. Rene Arnoux and Stefan Johansson failed to qualify on several occasions. In the midseason Guy Ligier showed Tetu the door.He was immediately signed up to for the Larrousse team but had to fight a court case with Ligier before he could begin work. He then began engineering for Larrousse, which was using a Lola-Lamborghini combination. This proved to be quite successful in 1990 but money was short and in 1991 the team had to switch to Brian Hart-tuned Cosworth engines. In midseason the team went in receivership, leaving Hart and Lola unpaid.Larrousse found a new backer and for 1992 did a deal with Robin Herd for the construction of an F1 chassis and did a new deal for Lamborghini engines. Results were poor and debts rose in 1993 and 1994. When Larrousse failed to pay for the 1995 chassis, the team went out of business.Tetu stayed with Larrousse when the team was resurrected as a sportscar operation.