The world-premiere of the 140 series SEC coupes took place in Detroit in 1992, the premiere in Europe was two months later on the Geneva Motor Show.
For the time being two variations were offered: the 500 SEC and the 600 SEC which were similar in its motorization to the corresponding 140 series sedans. Ex works both were equipped with numerous extras and represented the top models of the passenger car programme.
In technical terms the SEC coupes were based on the S-Class sedans presented in 1991; in terms of styling they were, however, clearly more autonomous than their predecessor models of the model series 126.
Analogous to the other passenger car types new type designations were also introduced with the S-Class coupes in June 1993; the 600 SEC, for instance, thus became the S 600 Coupe.
The type label on the deck lid now only documented the displacement and the class to which the car belonged but not the form of the bodywork visible anyway.
In March 1994, that means two years after its première in Europe, on the Geneva Motor Show, the coupe family was given support by the S 420 Coupe which since then has been seen as the lower-priced model for beginners and is equipped with a 4.2-liter 4-valve V8 like its four-door counterpart in the line of the sedans.
Two fundamental technical novelties were available for the first time in the S 600 Coupe: In May 1995 a completely new developed 5-speed automatic transmission with slip-controlled torque converter, lockup clutch and electronic control was introduced that made for a reduction in the fuel-consumption because of its ingenious electronic control.
Regarding weight and dimensions, too, these novelties were successful; the “new automatic transmission” is considerably lighter and more compact than comparable gearboxes with five speeds and, moreover, it can be produced more economically as the number of individual parts could be reduced by nealy 40 %.
Another innovation of basic importance was introduced at the same time and, since then, belongs to the standard delivery programme of the S 600 Coupe: the “Electronic Stability Programme” (ESP) supporting the driver in driving mistakes by counteracting the unstable moment through specific braking thus contributing to driving safety.
Since September 1995 the electronically controlled automatic transmission is also used with the 8-cylinder engines; since the same time the ESP is available for both models on request. In June 1996 the type designations for the coupes were changed once again.
In June 1996 the type designations for the coupes were changed once again.
The change of the name was not an end in itself but should show that the large coupes had taken over the role of the pacemakers for a whole family of coupes. The CL coupes were also slightly modified in terms of style: Externally visible were the revised bumpers with the integrated sensors for the ultrasonic parking aid “Parktronic” being part of the standard delivery programme.
Through this parking aid the backup markers were no longer needed in the rear wings. Other remarkable novelties were xenon headlights with dynamic headlight-range adjustment, a tempomat with speed-limiter, standard sidebags as well as a seat identification system for the front passenger seat.
Assembly of the CL models ceased in September 1998, almost six years after the commencement of standard production. Afficionados of the big Mercedes-Benz coupe will have to be patient as the successor model is not scheduled to be launched until the fall of 1999. A total of 26,022 units of 140 series coupes were produced at the Sindelfingen plant.