PSA TU engine

The TU family of small inline-four piston engines by PSA Peugeot Citroën were introduced in 1986 and used in the Peugeot and Citroën range of cars. It was first installed in the Citroën AX in October 1986, replacing the X family, although it shared many components with its predecessor. The TU was available in either petrol or a naturally aspirated diesel variant, the latter called TUD. The TU engine was distantly related to the older X-Type engine – sharing a similar overhead camshaft architecture, but the key differences are the belt driven camshaft (the X is chain driven), and that the TU is mounted in a conventional upright position with a separate, end-on mounted transmission and unequal length drive shafts. The X engine, by comparison, had an integral transmission mounted on the side of the crankcase (giving rise to its popular nickname the "suitcase engine"), sharing a common oil supply and was mounted almost lying flat on its side within the car. After the engine debuted in the Citroën AX in 1986, it quickly began replacing the X engine in most of its remaining applications – the Peugeot 205, Citroën BX and Citroën C15 had all transitioned by 1988 whilst it replaced the Simca "Poissy" engine in the Peugeot 309 in 1991. It was also used in the following cars: Citroën: AX, Saxo, C2, C3, C4, BX, ZX, Xsara, Nemo and Berlingo. Peugeot: 106, 206, 207, 306, 307, 405, Bipper, Partner and Hoggar, the Iranian Peugeot 405 and Peugeot Pars as well as the IKCO Runna. The TUD engine was only used in 11 cars of which 6 were non-PSA models: the Citroën AX, Citroën Saxo, Citroën Xsara; Peugeot 106, Rover Metro/100-series, Nissan Micra, Maruti Suzuki Zen D/Di and Maruti Suzuki Esteem D/Di and IKCO Samand, and the Tata Indigo...