The R107 SL debuted in Spring 1971 as an ageless open-top roadster that would please the world for decades to come. The R107 proved to be ahead of its time in nearly every regard. This platform was so well built, safe, and heavy that Mercedes-Benz internally referred to it as “the Panzerwagen.”
About 800 pounds heavier than the preceding W113 Pagoda, the R107 body shell was also much stronger. Both the weight and strength came from altering structural members, resulting in a defined crumple zone. For example, the A-pillar served as both the windshield frame and roll cage structure. Then the windshield and hardtop rear window were glued into the frame to increase rigidity. The removable hardtop could withstand a considerable amount of weight. Door panels were reinforced to resist side impact. Door handles were designed to be openable in the event of a collision. The fuel tank was located over the rear axle, protecting it in the event of a rear end collision.
Safety and ergonomics do not stop with the exterior – the interior has a range of safety innovations. All R107s had a telescopic collapsible steering column, and a foam-padded safety steering wheel, which later held an airbag. Three-point seatbelts with an inertia reel were standard; this meant that the seatbelt could comfortably accommodate drivers of all heights and sizes. Interior surfaces were padded. Later vehicles benefited from a driver’s knee bolster.
Safety features evolved over the course of production, with a driver’s side airbag becoming available beginning model year 1982, and standard from 1986. Disc brakes became available in the United States in 1985 and standard in 1986.
350SL/450SL 1972-1980
Across its 18-year production, there were several engine choices for the R107. The first U.S.-Spec 1972 model was the 350SL, fitted with the M117 4.5L V-8, rated at 190 horsepower. U.S.-spec engines used lower compression due emissions regulations. After only one year, the 350SL was renamed the 450SL for the 1973 model year to suit its displacement.
Beginning in 1974, there were several changes to the R107 to meet U.S. regulations. The infamous U.S.-Spec bumpers made their first appearance, replacing the sleek body-hugging bumpers of earlier cars. In 1976, the 450SL was fitted with Bosch K-Jetronic fuel injection, which replaced the Bosch D-Jetronic system found in earlier cars. All 450SLs were paired with a 3-speed automatic transmission. Throughout the production of the 450SL, the climate control system was updated twice. SL models until 1978 featured a manual climate control system, whereas 1978-1980 models featured a troublesome servo-based automatic climate system.
From 1974 to 1979, the 450SL was rated at 180 horsepower. The 1980 450SL, with 160 horsepower, reached 60 miles per hour in 11.7 seconds, whereas the original 350SL was one second quicker to 60. The final drive ratio was 3.07 or 3.06 from inception to 1979. It changed to 2.65:1 only for the 1980 model year when the power went down to 160 horsepower, but torque went up slightly.
380SL 1981-1985
The year 1981 introduced the Mercedes-Benz 380SL, powered by a 3.8L V-8 reincarnation of the M117, designed with fuel economy in mind. Power loss was inevitable, although not terrible. The new 380SL made 155 horsepower. The reduction in power was almost unnoticeable due to a new 4-speed automatic transmission that improved acceleration while lowering engine RPM on the highway for increased fuel economy, improved at 17.5 mpg.
The major flaw that plagues the 380SL is the single-row timing chain fitted to model years 1981-1983. The chain is notorious for snapping, but most models have been remedied under warranty by Mercedes-Benz by fitting a double-row timing chain. 1984-1985 380SL models came with double-row timing chains from the factory, which allowed these engines to reliably endure hundreds of thousands of miles. Other changes to the 380SL included an updated automatic climate control system, a redesigned lower front air dam, an aluminum hood, a smaller safety-steering wheel, redesigned headrests, and ABS was added for the 1985 model year.
560SL 1986-1989
Considered the best and most desirable of U.S.-Spec R107s was the 560SL. Introduced in 1986, the 560SL offered the largest engine ever fitted to the R107, a 5.5-liter M117 with a four-speed automatic transmission. The 560SL proves once again that there is no replacement for displacement. With an output of 227 horsepower, compared to the 155 horsepower of its predecessor, this new model was very welcome. The 560SL could reach 60 miles per hour in just 7.7 seconds, a very noticeable improvement.
The 560SL brought much more to the table than just power. This SL had larger brakes with standard ABS, and a limited-slip rear differential which improved overall power delivery. Speaking of power delivery, the 560SL adopted W126 S-Class front suspension and upgraded rear suspension, which reduced “rear squatting” under acceleration. A driver’s-side airbag was standard on all 560SL models.
Other upgrades included new 15-inch “manhole cover” alloy wheels – the previous model rode on 14-inch Bundt wheels – a redesigned air-dam that noticeably improved appearance, redesigned flush door handles, new leather seats with thicker side bolsters, updated sun-visors with mirror/lighting system, and a government-mandated third brake light.
The 1986-1987 560SL had a more obtrusive third brake light towards the middle of the trunk lid, whereas 1988-1989 models featured a subtler third brake light near the edge of the trunk lid. The 560SL is special because it mated modern performance and technology with a classic design. When new, the 560SL bodywork was considered dated by some, but in the eyes of a Mercedes-Benz enthusiast, it was a well-seasoned cruiser.
European and grey-market models
Several other R107 models were offered overseas and were not available in the United States. These models included the 6-cylinder 280SL (1974-1985), the 300SL (1985-1989), the 350SL (1971-1980, featuring an M116 3.5L V-8), 420SL (1986-1989), and the 500SL (1980-1989). Many U.S. enthusiasts turned to grey-market importers, purchasing models from overseas. This was mainly due to the fact that European cars were always more powerful and offered more options. This Buyers Guide focuses on U.S.-spec models.
C107/SLC
The C107 was introduced as a fixed-roof sports coupe variant of the R107. The SLC was sold alongside the two-seater SL roadster from 1973-1981. While the R107 project was under development in the 1960s, there was concern that open-top cars would be banned in the United States due to tightening U.S. safety regulations. Mercedes-Benz took a risk and continued with R107 development. An additional proposal was made to derive new coupes from a lengthened R107 chassis, rather than a platform traditionally based on the S-Class sedan. The resulting coupe was 14 inches longer than the roadster, with room for four adults. The coupe offers a pillarless side profile and charming C-pillar window louvers known as a “venetian blind.” Models offered in the U.S. included the 350SLC, 380SLC, and 450SLC. Apart from the 450SLC 5.0, most variants were built according to contemporary R107 specifications and timeline.
Reasons to buy a R107
• It's a road fortress with timeless styling, modern safety features, unparalleled build quality, and stellar reliability.
• R107 models are available at all price points. 500SL and 560SL models tend to be on the more valuable end of the spectrum.
• R107s are all but guaranteed to hold their value
• Parts are readily available, as is technical know-how.
Reasons not to buy a R107
• Expensive to sort out poor examples.
• Fuel economy was never great, regardless of model.
• They do not like to sit parked. A garage queen may require a fuel system overhaul.
• Rust is endemic.
Checkpoints
• Rust is common on the inside and bottom of the front fenders, rocker panel, jack points, inside the tonneau cover, inside the spare tire well, below the floors.
• Old rubber suspension bushings often require replacement.
• Play in the steering wheel is common, steering boxes can present themselves as an issue. This combination severely distracts from the car's excellent handling.
• Electronic fuel injection issues are common, as are fuel pump issues. Often caused by a lack of exercise.
• Oil leaks: Head gasket leaks towards the rear of the engine. Upper oil pan. Rear main seal. Transmission-pump seal will overflow if the car has sat for too long.
• Automatic-climate control systems finicky, expensive to repair.
• Inspect for double row timing chain on 380SL models 1981–1983.
• Timing chain, timing chain tensioners, timing chain guides are an issue of attention. Regardless, replace chain tensioner and guides every 10 years / 100,000 miles.
• Soft top can leak over time from several spots. Rear soft top window can also shrink, fade, turn yellow.
Finally
A true blend of the classic and modern, the sporty R107 has endured to become a contemporary cultural benchmark, combining eternal styling with excellent safety, build quality and durability. With such a large production run over so many years, finding just the right R107 should be easier for the enthusiast than with almost any other vintage Mercedes-Benz.