In 1993, when the W202 was introduced as C-Class, the traditional naming convention (numbers, plus letters) was reversed, with a leading letter identifying the line (As of late 2017, A, B, C, CLA, CLS, E, G, GLA, GLC, GLE, GLS, S, SL, SLC, V and X are in active use). From then on, the long-wheelbase models (formerly "SEL") and the regular-length models (formerly "SE") are both labeled with the prefix of "S" regardless of length. For example, both 500SE and 500SEL are now labeled as S500/S500L, with fuel injection being standard by now anyway. The W221 S-Class has been available in four trim levels; the numbers are given in ascending order to denote more upscale models (e.g. S500 (S550 for US)/S600/S63 AMG/S65 AMG etc.). In official Mercedes-Benz publications and on vehicle nameplates, a space between the letter and numbers is customary (e.g. S 600).The Mercedes-Benz S-Class, formerly known as Sonderklasse (German for "special class", abbreviated as "S-Klasse"), is a series of full-sized luxury flagship vehicles produced by the German automaker Mercedes-Benz, a division of German company Daimler AG. The S-Class designation for top-of-the-line Mercedes-Benz models was officially introduced in 1972 with the W116, and has remained in use ever since.
The S-Class has debuted many of the company's latest innovations, including drivetrain technologies, interior features, and safety systems (such as the first seatbelt pretensioners).[5] The S-Class has ranked as the world's best-selling luxury sedan, and its latest generation, the W222 S-Class, premiered in 2013. As in previous iterations, the W222 S-Class is sold in standard and long-wheelbase versions; I4, V6, V8, V12, diesel and hybrid powertrains are offered. All models built in Mexico or sold in the United States are available in long wheelbase only.
In automotive terms, Sonderklasse refers to "a specially outfitted car." Although used colloquially for decades,following its official application in 1972, six generations of officially named S-Klasse sedans have been produced. Previous two-door coupe models of the S-Class were known as SEC and later S-Coupe. In 1996 the S-Class coupe was spun off in a separate line as the CL-Class, however as of June 2014, it has been re-designated as the S-Class Coupé for the 2015 model year, doing away with the CL-Class. In 2016, the S-Class Cabriolet, internally named A217, was introduced with three variants: the S 550 Cabriolet, the Mercedes-AMG S 63 Cabriolet with 4Matic, and the Mercedes-AMG S 65 Cabriolet.The Mercedes-Maybach S 650 Cabriolet, based on the S 65 Cabriolet, was announced in 2016.