1978 Mercedes-Benz 450SL - Classic Car Price Guide

History of the 1973 - 1980 Mercedes-Benz 450SL

The Mercedes-Benz SL underwent something of a revolution when the R107 was launched in April 1971. But then, it probably needed to, as replacing the old Pagoda was always going to be one of the toughest gigs in the industry. But what Mercedes-Benz cooked up was perfect for its time, featuring a V-8 line-up, and smart and contemporary styling, as penned by Joseph Gallitzendörfer and Friedrich Geiger.

The move to 3.5-litre M116 (used in the Mercedes-Benz 350SL) and 4.5-litre M117(used in the Mercedes-Benz 450SL) V-8 engines clearly showed that Mercedes-Benz had refocused the SL—and although the smaller of the two had little more power than the outgoing straight-six 280SL, it boasted far more torque, accentuating the effortlessness of the drive and cementing the SL's position as a boulevard cruiser. The new SL wasn't much quicker than the old one, but was far more restful thanks to taller gearing.

The 350SLC and 450SLC joined the SL in October 1971, and unlike the previous flagship coupe in Mercedes-Benz's range, this one was closely related to the range's roadster and not its top-flight saloon. To create the SLC, Mercedes-Benz effectively took the R107 roadster, added 14 inches to its wheelbase, added a fixed roof, and squeezed in a small pair of rear seats. Given that there was a legion of engineering changes made to the SL to create the SLC, the weight gained—a mere 70kg—was really quite impressive.

In October 1974, and in almost perfect timing in the aftermath of the 1973 energy crisis, the SL was expanded to receive the excellent 2.8-litre twin-cam to create the 280SL. Given that certain buyers were downsizing, and existing Pagoda owners greeted the new 280SL warmly, it's no surprise that the six-cylinder roadster went on to sell so well. The same might not be said for the 450SLC 5.0, which joined the range in 1977 as a homologation special to support the following year's factory rally joined the line-up. With the all-new aluminium V-8, it was easily the fastest model in the range.

The SL range was updated in 1980, receiving a few small styling tweaks, but the main changes were reserved for under the bonnet. A raft of technical changes to reflect the new technology that had been included in the 1979 S-Class resulted in a more efficient, and faster SL—especially, as the main change was the fitment of a five-speed manual gearbox as standard.

Throughout the 1980s, the improvements continued. The V-8s were upgraded to 380SL- and 500SL-specification, which were then further tweaked for improved fuel consumption in September 1981. Further running changes included increasing the six-cylinder 280SL's engine capacity to 3.0-litres in 1985, and the arrival of the 420SL to replace the 380. The best was definitely left for last, though, with the launch of the impressive 560SL at the top of the range in 1985. Although with 227 bhp, it was no more powerful than the 500SL, additional torque resulted in a more seamless drive and slightly improved performance, with a 0-60mph time of less than 7 seconds.

The R107-generation Mercedes-Benz SL remains popular to this day, with plentiful choice, and for good reason. It's as solid as you'd expect for a Mercedes-Benz of this age, with remarkably few weaknesses—corrosion around the edges being one, as are the 560SL's oil leaks and the 380SL's timing chain problems. But that's a remarkably short list for a car of this age, and testament to the integrity of the original car. In the end, the R107 SL remained in production since 1989 – a near unprecedented run for a Mercedes-Benz – although the C107 SLC was replaced in 1981, with the arrival of the gorgeous S-Class based SEC. The final production tally for all SLs and SLCs is 300,175.

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Year Make Model Submodel Body Type Engine Average Value
1978 Mercedes-Benz 450SL Standard Convertible
£15,900