When BMW introduced a new 7-Series (E32) in 1986, a first post-war German passenger V12 engine, M70, was offered. This surprise announcement forced Mercedes-Benz to delay the introduction of the W140 by eighteen months to 1991. The delay allowed Mercedes-Benz to develop the new V12 engine and to rearrange the engine bay to accommodate the gargantuan V12 engine along with upgrading the brake system. The final development prototypes were completed in June 1990, with pilot production models being built from June 1990 to January 1991.