Understanding why We Love Them: The Mercedes-Benz R129 SL, with Dean Laumbach and BaT Staff!

It’s been too long since we’ve published “Why We Love Them,” a series of articles paying tribute to some of BaT’s favorite vehicles from the past. Era, genre, and country of origin aren’t as important as character—that hard-to-define “something” that all the best cars seem to have. This time around, we’re including input from members of the BaT community and staff as we discuss the R129 Mercedes-Benz SL roadster in all its variety.

Dean Laumbach, one of the foremost Mercedes-Benz experts on BaT, sets the scene: “In the mid 1990s, I was employed in the Financial District in New York City. It seemed to me that it was a right of passage for a Wall Street big shot to own a R129. The first floor of the Battery Park Garage, two blocks from Wall Street, looked like a Mercedes-Benz showroom with all the V8 and V12 models parked there daily.”

In 1989, after nearly a decade of delays, the R129—successor to the R107 SL—launched in the European market, and it departed for North America the following year. It’s usually the case that a manufacturer’s upper-echelon cars define the styling for the rest of the lineup, but the new SL was the last in the Mercedes lineup to adapt the design language first established by Bruno Sacco in 1982 with the W201 C-Class. The car came by the look honestly, based as it was upon a foreshortened W124 chassis. Slab-sided, with a raked grille and rectangular lights mounted nearly flush, the car was trapezoidal in profile, and optional contrasting lower cladding (known as “Sacco boards”) accentuated its billet profile. This was no visual illusion—the R129 weighed in around 4,000 lb., give or take, depending on the spec. Sacco considered it his best work.

Again, Dean: “The build quality of the R129 is unmistakable as soon as you close the driver door. The ‘bank vault’ sound upon closure is a characteristic that you will not get from the cars of today. While the R129 is not a true sports car, it has a tight drive quality that is very uncharacteristic of most drop tops. All three engine variants (six-, eight-, and twelve-cylinder) are literally bulletproof with proper maintenance, and the safety features of the R129 were the benchmark for drop tops of this era.”

Production of the R129 was handled by MB’s Bremen plant to handle the high projected demand, and the cars were built with a unique combination of automation and hand work. Final assembly took place in a star-shaped bay that allowed technicians to move between vehicles quickly, and completed vehicles underwent a 1,000-kilometer virtual test drive for quality-control purposes.

Many current R129 owners were just kids when the model was in production, and it made a strong first impression. Carter, a BaT staffer and current 500SL owner, recalls seeing one new at the MB dealership: “It felt like a leap into the future compared to my father’s [W113] 280SL; the sharp styling and low profile grabbed my attention—the flares, the super-low and long hood, that wide grille hiding a V8…It just seemed like the perfect convertible, but the $84k sticker price was otherworldly. My father bought me a R129 hat, and for good measure, a C11 World Champion pin. I still have both, and for a long time, it felt as close as I’d ever get to owning one. Still, the cars always caught my attention whenever I would see one on the road.”

With just a few options, a V8-powered 500SL could easily crest the $100k mark. In return, buyers got a vehicle with automated features that were the stuff of science fiction. As the advertising proclaimed, it was “Engineered like no other car in the world.” Electrical, hydraulic, and mechanical systems worked together in harmony, performing a symphony of comfort and convenience tasks in several movements. With the press of a switch, 12 hydraulic cylinders unlocked, retracted, and stowed the convertible top beneath an integrated tonneau. Seats provided self-contained side-impact protection and featured cast magnesium structures, five separate motors, and integrated shoulder harnesses. Self-leveling suspension was standard in many markets on the 500SL and 600SL, and the optional Active Damping System adjusted the ride and suspension height utilizing data from sensors measuring speed, acceleration, braking, cornering force, steering angle, and suspension movement. Remember, this was 1990.

From the start, all came with dual airbags, three-position seat memory settings, and a hidden roll hoop that deployed in 0.3 seconds in the event of an impact greater than 4g or full extension of the rear suspension (indicating a rollover).

It’s easy to see how a vehicle of this complexity could become a nightmare if not properly maintained. To quote Dean, “Deferred maintenance will require a significant investment post purchase to sort out prolonged periods of inactivity and general neglect. Insist on proof of repairs of known faults being addressed, such as soft-top hydraulics and the functionality of the HVAC system. Suspension and braking systems are simple and straightforward repair items as the more modern complexities of these systems were not employed in the R129. Parts for these R129 components are also widely available from Mercedes-Benz and also higher quality aftermarket companies.” When discussing the R129 with our colleagues, one told us of a NASA engineer friend who was plagued by electrical and HVAC gremlins on his neglected example, and made use of the space agency’s tools to rectify certain issues. The good news is that most R129s were purchased by people who could afford to service them properly, and low-mileage examples with documented service and ownership history aren’t uncommon.

Many small details changed over the R129’s 12-year production run, and there were also a few more notable evolutions and special versions. Per Dean, “The pre-merger AMG R129s (1999 and earlier) are the most sought after, but an ’01–02 model, which came standard with all the AMG Styling Package features, is my car of choice for ‘bucket list’ ownership.”

Let’s talk about those evolutions:

1990–1993: The First Run

Initially, the R129 was released with the 3.0L M103 inline-six as the base engine, but this quickly changed to the newer M104 in the same size: a DOHC, 24-valve engine with variable valve timing (known as the 300SL-24 in Europe). The six-cylinder engine is viewed as robust and reliable, though its head gasket is a known weak point.

The M104 was the only powerplant that could be paired with a manual transmission in the R129, and it was the same dogleg five-speed as the one in the Cosworth-tuned 190e 2.3-16. The manual was offered globally up to 1993—the best data states that around 400 were imported to the US. We’ve listed 21 five-speed examples to-date, including a Euro-spec version. The optional and more common automatic transmission was a four-speed.

The R129 was the first car to get MB’s 5.0-liter M119 V8, an all-aluminum, dual-overhead-cam mill good for a quoted 322 horsepower in US trim—likely a conservative number. The engine featured four valves per cylinder with variable timing on the intake cam, and was initially equipped with Bosch K-Jetronic mechanical fuel injection (CIS, if you came here from the Porsche world), but soon transitioned to computer-regulated KE-Jetronic.

At the top of the heap was the V12-powered 600SL, introduced globally in late 1992 as a 1993 model. The engine, known as the M120, was a 6.0-liter, all-aluminum, DOHC, 48-valve design that delivered its 389 horsepower and 420 lb-ft of torque in a velvet-lined briefcase. The 600SL was never intended to be a sports car, but indifferently bested many of its sports car contemporaries with ease. Car and Driver described it thusly; “Like a nuclear-powered hovercraft. Like the Concorde, or the bullet train. Phenom­enal. To talk numbers is to bourgeoisify the experience. Suffice to say that the Mercedes-Benz 600SL is quicker than a Ferrari 348tb, a BMW M5, and many other exotic sports and GT cars.” Exterior differences were beyond subtle—a different number on the badge, and a slightly elongated front bumper to accommodate the longer engine. All were fully loaded from the factory with an integrated cellular telephone, a six-disc CD changer, Adaptive Damping Control, and heated seats. Lumbar support and color scheme were the only options left to choose. The M120 V12 would would power the range-topping 600SL/SL 600 until the end of the run, even while the new W220 S-Class and CL were given the inferior M137 in the late 1990s.

1994–1995: Mechanical Updates and a New Badge

On the outside, the biggest change for 1994 was the badge—the SL initials were placed ahead of the three-digit model designation, because why not? The changes under the skin were more significant. The stick shift was offered only on the base SL280, and was rarely selected. Six-cylinder engines were now offered in 2.8 and 3.2 liters, reflected in their badging, and the SL320 was the base model for the US, making 228 horsepower.

That same year, the M119 V8 became an open-deck design with sleeved cylinders and received an updated Bosch LH-Jetronic digital fuel-injection controller utilizing a mass air flow sensor. Apparently, even investment bankers had been put off by the 500SL’s fuel consumption, and the new, more efficient system required a minimal haircut of seven horsepower. One year later, OBD-II compliant Bosch Motronic and coil-on-plug ignition were introduced, making diagnosis and maintenance much easier. From 1996 on, all cars except for the 280 received a new five-speed automatic transmission. Many owners report that the middle years ranging from 1993-1998 are the most reliable for fans of the M119, though pre-1996 cars famously suffer from biodegradable wiring harness insulation.

1996–1998: The First Facelift

Most of the first visual alteration was focused on the lower body, and two-tone color schemes were struck from the list of options. The Sacco boards were more contoured and the three straight vents behind the front wheel became two ovals. Bumper covers got a softer shape with an integrated rub strip, and the lower grille opening and fog lights were given more rounded shapes. New, eight-hole and 12-hole wheels replaced the Gullideckels as the 16″ option, while the 17″ non-AMG wheel was the wide-spoked five-star “Albali.” Side airbags and clear corner markers became standard, and xenon headlights became optional (standard on the SL600), as did a new panoramic glass-roof hardtop. The previous power-operated rearview mirror was deemed unnecessary, and its replacement integrated a programmable garage door opener. An emergency Brake Assist feature was released, as well.

As Mercedes increased their involvement with AMG, the tuner’s name began appearing in the regular catalog of optional equipment. The SL1 AMG Sport Package was made available in late 1996 (usually distinguished by “Sport” fender badges), comprising more angular bumper covers, sculpted rocker moldings, and 18″ Monoblock wheels. The SL2 option package added xenon headlights and heated seats. Rain-sensing wipers became standard in 1997.

1999-2002: The Final Boss

For model year 1999, the SL280 and SL320 received Mercedes’ first production V6—the M112, which was a 90º design with three-valve, twin-plug SOHC cylinder heads and variable-length intake runners. This architecture was shared with the new M113 V8, which made 302 horsepower in US trim. This engine was lighter, more efficient, and less expensive to maintain than the mighty M119, and some R129 enthusiasts resent it for that. Still, it was and remains a pretty reliable powerplant, and for some owners, the more modern features on later-model cars outweigh the loss of the 32-valve motor.

In the US, it was the end of the Clinton era and the height of the Dot-Com Boom. American buyers were flying high. Most didn’t even consider the six-cylinder engine, and Mercedes dropped it entirely for our market. The styling was subtly softened again, this time with contoured taillights, body-color door handles, and rounded side mirrors. Mercedes-Benz completed their acquisition of AMG in 1999, and the AMG Styling Package became standard on all cars for 2001–2002 with revised five-spoke 18″ AMG wheels on the V8 model, while V12-powered cars got the same three-piece wheels as the SL72 AMG. The updated interior included a restyled steering wheel, chrome instrument bezels, and pleated leather instead of perforated upholstery.

Production peaked at 26,000 per year in 1991 and 1992, and best estimates hold that 204,940 cars had built by the end of the run. To keep interest up as the model aged, the company spun off special editions beginning in 1995, a strategy they turned to with increasing frequency in subsequent years. Now is as good a time as any to run down the list.

Special Editions:

1995 Mille Miglia Edition: 630 Brilliant Silver cars celebrated the 40th anniversary of Stirling Moss’s 1955 victory in the Mille Miglia. Like Moss’s car, most were equipped with an inline-six. Interiors were trimmed in two-tone black-and-red leather with carbon fiber trim. Racy six-spoke wheels were borrowed from the 190E 2.5-16 Evolution II and checkered flag details were added to the fender vents.

1996 US 500 Edition: Forty SL500s served as parade cars for the inaugural U.S. 500 race (held in Michigan opposite the Indy 500 during the CART/IRL dispute). All were reportedly equipped with the Sport Package, AMG Monoblock wheels, and ESP, and were finished in red, white, or blue.

1997 La Costa Edition: A run of 30 examples were built to commemorate the Mercedes Championships golf tournament at La Costa Resort and Spa in California. These were finished in Calypso Green over green and black leather, and featured the AMG Styling Package.

1997 40th Anniversary Edition: The 40th Anniversary Edition comprised 750 cars (500 SL500s and 250 SL320s) to celebrate four decades of the Mercedes-Benz SL roadster. Each was finished in Crimson Metallic (500SL) or Quartz Blue Metallic (320SL) with gray-tinted burl wood (SL320) and 190E 2.5-16 Evolution II seven-spoke wheels (SL500).

2000 Designo Slate Blue and Designo Black Diamond Editions: The Designo cosmetic packages for model year 2000 included special paint and interior finishes. Color-shifting Designo Slate Blue came with 17″ Albali wide-spoke wheels, blue and black Nappa leather upholstery, and special gray-stained curly maple interior trim. Designo Black Diamond offered pearlescent black metallic paint over black and red Nappa leather upholstery with carbon fiber accents in place of wood.

2000 SL Edition: Yes, the R129 got a special edition named after itself. The SL Edition came in Designo Mystic Blue and featured special fender badges, exterior brightwork, two-piece BBS wheels later adopted on the Silver Arrow Edition, an engine-turned instrument panel and shifter surround, perforated leather seats, and dark gray birdseye maple interior trim.

2001 Formula 1 Edition: To celebrate the return of Formula 1 to the US, 20 cars were finished in Brilliant Silver Metallic over black Nappa leather. Painted and engine-turned interior panels were joined by white accents on the steering wheel and shift knob, recalling the colors of the McLaren-Mercedes MP4-16 F1 racer. The cars also received checkered flag fender badges and 18″ AMG five-spoke wheels.

2000–2001 Final Edition: This was a European special edition of approximately 700 cars, 247 of which were finished in Silver Arrow Metallic and the balance in Designo Black Metallic. The package was available with all engines and included 18″ AMG five-spoke wheels, Exclusive Nappa leather with silver contrast stitching, and the return of perforated seat inserts. Curled Maple wood trim, illuminated door sill plates, and Final Edition fender badges and interior decals rounded out the offering.

Silver Arrow Edition: But wait! As it turned out, the Final Edition was not the final edition! The R129 ceased production in 2001, but continued to sell in the US as a model-year 2002 vehicle. The Silver Arrow package was specified for around 2,000 cars—1,450 SL500s, 100 V12-powered SL600s, and 100 right-hand-drive cars for the UK market, just so they didn’t feel left out. All were finished in Silver Arrow Metallic and received Exclusive Leather interiors in Black Nappa (SL600) and Black Nappa with light gray inserts (SL500). Other defining features included two-piece BBS Albireo wheels, cross-drilled brake rotors, silver-painted calipers, polished stainless steel exhaust tips, black birdseye maple interior trim, white gauge faces, brushed aluminum pedals, and Silver Arrow markings inside and out. Each car also came with an aluminum Silver Arrow briefcase containing a special keyring, a certificate from Mercedes-Benz, and other factory literature.

AMG Editions

At this point we’ve spilled quite a bit of ink, so we will cover the AMG-tuned cars briefly, especially since all are pretty rare. The first pre-merger AMG conversions were specified by individual owners, who sent their M119-powered cars off to Affalterbach to have their engines enlarged 6.0 liters and output pushed to the neighborhood of 370 horsepower. Suspensions were lowered and tuned, special bodywork and wheels fitted, and speedometers replaced with 300 km/h AMG-branded units. After 1993, these cars were badged SL 60 and given an additional power bump to 381 horsepower. Some 633 were purchased through Mercedes-Benz dealerships, though AMG also continued to convert customer cars during this era.

Through the beginning of the merger era, from 1998–2001, the SL 55 AMG was the most basic tuned version. Sixty-five were reportedly built, and these made 354 horsepower from a 5.4-liter M113 V8. At the upper end of the range were three V12-powered cars: pre-merger, the 7.1-liter SL 70 (150 built) made around 489 horsepower, and the 7.2-liter SL 72 (35 built) ponied up 525. But AMG had room to crank the dial up one more with the 7.3-liter SL 73 (85 built), which used the M120-based M297 V12 also found in the CLK GTR Straße and later the Pagani Zonda. Japan was the largest market for most of the AMG R129s, though they were also sold in Europe and other regions; the Sultan of Brunei even snagged a few for his personal collection.

The R129 Market on BaT

There have been over 1,400 R129 auctions on BaT as of this writing, and the full model page chart shows everything from six-cylinder drivers to serious outliers like the AMG cars that compress the more typical results. The version above aggregates sales under $100k within the last two years and shows that the vast majority of cars hammer between $10k and $30k, with premiums placed on very low-mileage examples and SL600s or special editions. The R129 remains for many an accessible, eminently drivable classic with plenty of modern comforts and timeless styling.

We’ll end with Carter, the BaT staffer who snagged his first-generation Cabernet Red 500SL after years of patience. “After a fair amount of paint correction, the car looks pretty good! It is not without fault—many of the early plastic items on the interior still need replacing, and it has some typical R129 issues. The driving experience is lovely; it can accelerate like a sports car but is also so content to burble along in near silence with smooth shifts. I have some maintenance to catch up on this spring, but I still have to pinch myself that the car sits in my garage. It was an aspirational dream when I was a teen, and continues capturing my imagination today. It gets thumbs up and passersby to stop and comment. What a lovely car.”

If you’re looking for a well-presented buyer’s guide, we appreciated the video above—and not just because the creator uses a lot of BaT data.

Many thanks to Dean Laumbach and BaT staff including Carter, Ryan, and others who shared their experiences for this article.

Sources:

M119 Deep Dive on r129.co

M120 Deep Dive on r129.co

SL Buyer’s Guide on slshop.cpm

Pelican Parts R129 Tech Article Archive

R129 brochure collection at ourmercedesbrochures.nl