The Mercedes-Benz W140 was a series of flagship vehicles manufactured by the German automotive marque Mercedes-Benz. The car premiered at the Geneva Motor Show in March 1991, with the first examples rolling off the production line on August 6, 1991. Short (SE) and long (SEL) wheelbase sedans were offered initially, as well as the coupé (SEC) body style from January 1992. Like all Mercedes-Benz lines, the W140 S-Class was rationalized in late 1993 using the new "letter-first" nomenclature. The SE/SEL/SEC cars were renamed the S-Class, with alphanumerical designations inverted. For example, the 500SE became the S500, and the 500SEL became the S500L. In 1996 the coupé models following a mid-life update were separated into the CL-class. The W140 series S-Class was superseded by the W220 S-Class in 1999 after an eight year production run, the coupé by the C215 CL-Class for model year 2000.
For details like this, the W140 is often known as the last Mercedes to be "overengineered," a Mercedes trait that was costing the company in product delays and overbudgeting. For the consumer, the W140 cost a considerable 25 percent more than its predecessor, the W126.