Volvo began production of straight-six engines with the 1929-1958 Penta DB flathead engines. The company resumed production in 1969 with the Volvo B30 overhead valve petrol engine, followed by the straight-six versions of the Volvo Modular Engine introduced in 1995 and then the Volvo SI6 engine introduced in 2006. As Volvo switched to transverse engined platofrms in the 1990s (due to the adoption of front-wheel drive), models such as the 1998-2006 Volvo S80 used the uncommon design of a transversely-mounted straight-six engine. The length of the engine/transmission was minimised by using a short transaxle package and relocating engine ancilleries from the front and rear of the engine. Production of Volvo straight-six engines ceased in 2015.