In September 1985 at the IAA in Frankfurt, a completely revised SL model range was presented. In addition to a discreet facelift which primarily the front spoiler and the wheels concerned, and improved front suspension was primarily a restructuring of the engine range in the foreground. A newly designed 3.0-liter six-cylinder in the intermediate range W nine months previously had 124 his first appearance, replaced, as with the S-Class sedan, the tried and true 2.8-liter DOHC engine. Thus, it was after 22 years of interruption of a sports car with the magic model designation 300 SL. New to the program was also a 4.2-liter V8 engine, which was caused by drilling of the 3.8-liter unit and this is now, replaced in the S-Class sedan and the SEC Coupé in SL. The 5.0-liter engine had also been modified; he was now equipped with an electronic ignition system and the electro-mechanically controlled Bosch KE-Jetronic and developed an output of 245 hp.
The most spectacular innovation in the engine range was a 5.6-liter eight-cylinder engine, which was developed from the 5.0-liter V8 by lengthening the stroke and mobilized an output of 272 hp. In this form, however, the new top unit was not in SL, but only in the S-Class sedans and coupés used. The 560 SL was not available in Germany and was export markets USA, Australia and Japan reserved; the local emission regulations forced the use of a disarmed engine variant which contributed only 230 hp SAE with catalytic emission control system. For many suffering SL fans from the „land of opportunity“ this nevertheless meant a revelation, they had yet to be content for years with the 157 hp SAE the 380 SL.
The production of the 300 SL – 560 SL ended in August 1989, more than 18 years after the series production of the 350 SL was started; so that the SL series had 107 established an in-house record which hardly likely to be on offer: In the entire history of the house there is no other car series, which was produced over such a long period. Overall, in Sindelfingen 237,287 vehicles, a figure which demonstrates the great popularity of the 107ers impressively emerged.
Succeeding served three SL models of the 129 series, which were presented to the public in March 1989th Mass production was already under way at this time.