Widely celebrated as a prime example of Mercedes-Benz over-engineering, the S-Class built from 1991 to 1998—chassis code W140—embodies the company’s relentless dedication to pioneering automotive technology, refinement, and quality. The result of a billion-dollar, decade-long project, the W140 S-Class debuted multiple production vehicle firsts, including double-glazed windows, electronic stability control, soft-close doors, and later, sonar-assisted parking.

BMW’s surprise V-12-powered 7-Series famously delayed the introduction of the W140 S-Class as Mercedes-Benz took time to counter with its very own 12-cylinder. The first series-production engine of its type for the company, the M120 V-12 is celebrated for its power, reliability, and refinement, much like the vehicle it was created for, dubbed the S 600 and the absolute pinnacle of luxury motoring throughout the 1990s.

The model’s superlative engineering and technology brought a 25 percent price increase over the outgoing W126 S-Class, which led to slower sales despite widespread acclaim. This prompted Mercedes-Benz to shift from the engineering-driven approach it took in developing the W140 S-Class to a market-driven focus for successive models, leading some purists to regard it as the last “true” S-Class.

Daimler-Benz originally gifted this 1995 Mercedes-Benz S 600 to Michael Leith as a reward for his Mercedes-Benz dealership’s sales success. Never officially titled or sold to a private owner, the vehicle has remained in Mr. Leith’s possession over the past 20 years and showed 95,480 miles on the odometer at cataloguing time.

Finished in Black Pearl Metallic over a black leather interior, it features an extensive list of standard equipment, including multi-zone climate control, numerous power-assisted amenities, adaptive dampers, and a high-fidelity sound system. Detailed service history from Mr. Leith’s Mercedes-Benz dealership records servicing back to 2012—the earliest kept in their current system—and includes, significantly, a 2024 replacement of the injection harness with an NOS unit.

Considered well ahead of its time when new, some features of the over-engineered W140 family of Mercedes-Benz S-Class models still have yet to be widely adopted in mainstream automobiles. As such, this single-owner S 600, presented in wonderful condition throughout, still commands respect today.