 The body had an exceptionally stiff torsional rigidity, a trait it inherited from the 1800s.The standard powerplant for the X6 range was a transverse mounted 2.2L OHC straight-six engine, based on the 1500/1750 Austin Maxi unit.At the time of the X6's introduction, it would have been the only car in production with a transverse straight-six-cylinder engine in the world.