Buyers Guide - 1955-1962 W121 190SL Coupe and Roadster

Bruce Adams


Buyers Guide – Buyers Guide - 1955-1962 W121 190SL Coupe and Roadster

The 190SL “Touring Sports Cars”

Article and photography by Bruce L. Adams

Designed as a grand touring car that would be sporty, graceful, and suitable for long-distance travel, the 190SL introduced in 1954 stood in marked contrast to the 300SL Gullwing coupe and roadster that were considered thoroughbred sports cars.

Today the 190SLs have become collectible in their own right, enjoyed exactly for what they were intended, their beauty and the pleasure of driving them.

To start, the 190SL weighs 500 to 1,000 pounds more than true sports cars of its day, totaling 2,557 pounds of curb weight. Equipped with a 1.9-liter 4-cylinder engine producing only 105 horsepower, the design was not destined for the racetrack.

The vision of Max Hoffman, Mercedes-Benz U.S. importer of cars in the early 1950s, prompted the introduction of the 190SL. Hoffman recognized a market opportunity in the United States for a second, lower-priced model to complement the 300SL.

Hoffman’s marketing strategy was to take advantage of the 300SL’s win in the 1952 Carrera Panamericana Mexican road race. He wanted to build on the Mexican win to sell Mercedes-Benz cars in the United States, anticipating good sales potential for two such sporty designs. The American auto market at that time was profitable for the manufacturers of European sports cars. The 190SL was officially introduced, along with the 300SL coupe, at the February 6, 1954, International New York Motor Sport Show, to much praise in the motoring press.


Two individuals led the way for the development of the 190SL. Rudolf Uhlenhaut was a brilliant Mercedes-Benz engineer who in the 1930s gained recognition in European Grand Prix racing with the successes of the Silver Arrows. In the postwar period, Uhlenhaut was the driving force behind the Daimler-Benz Board of Management’s March 1951 resolution to return to motor racing. In his 41-year career with Daimler-Benz, Uhlenhaut had as much impact on Mercedes-Benz products as anyone in the history of the company (see The Star, May-June 2010, pp. 48-51). He strongly influenced the first 30 years of the SL models.

The second individual was Maximilian Edwin Hoffman, an American entrepreneur of Austrian origin. With his keen marketing sense, he recognized that the SL’s racing successes in Europe and especially Mexico – on his very doorstep – could serve as a launching pad for the American market, and he left no stone unturned in convincing Daimler-Benz to this effect. He built a reputation for European cars in America, and did so by introducing American buyers to such brands as Alfa Romeo, Austin-Healey, Jaguar, Porsche, and Volkswagen. The Hoffman Motor Company in New York became the U.S. importer for Mercedes cars in September 1952.

Hoffman was utterly convinced that the SL’s motor-racing successes in 1952 must be put to use as an entry ticket to the American market. His conviction paid off: Hoffman was asked to attend the September 2, 1953, board meeting in Stuttgart to present his ideas and visions for the U.S. market. He demanded a production-version sports car based on the 300SL racing model, as well as an accompanying smaller sports car, with both models introduced at the New York International Motor Sports Show in February 1954 – five months later! The board passed a resolution to develop and produce two entirely new models, the 300SL and the 190SL, and to display exhibition models at the New York show. The minutes of the meeting document the decision to proceed with the project. Hoffman “sold” Daimler-Benz on his idea, offering assurances and the promise to import and sell the cars in large quantities.

The advertised price of the 190SL in 1955 in New York was $3,998, with the 300SL priced at $7,463. The 190SL outsold the 300SL by approximately eight to one. By 1961, the base price had risen to $5,129. According to factory figures, 25,881 190SLs were produced from 1955 to 1963. Production peaked in 1956 at 4,032 cars, and 1963 saw the least number produced, 104. An estimated 50 percent of the total number of 190SLs produced have survived, and restoration promises to preserve them.

Reasons to Buy a W121

  • Timeless design: Voted a Milestone Car by the Milestone Car Society. The car looks like it’s going 60 mph while sitting in your driveway.
  • Road handling and dependably safe road characteristics: The front axle wheels are individually mounted on double-wishbone transverse links with central coil springs and hydraulic shock absorbers. The single-joint swing rear axle is based on the proven M-B racing design.
  • Fully synchronized 4-speed gearbox: Synchronized manual transmission allows the driver to shift the car with ease and, important from a safety aspect, select the correct gear for any situation, enabling the driver to retain complete control of the automobile at all times. The 190SL gearbox is excellent for downshifting from a higher gear (third or fourth) to a lower gear (first or second), which allows the driver to use the car’s engine as a brake. This capability is particularly useful in maintaining handling control under icy and wet road conditions.
  • 921 and 928 engine: The engine heralded a series of similar engines for Mercedes-Benz. Its 1.9-liter overhead camshaft provides 105 horsepower at 5,700 rpm, a respectable figure. It proved tremendously durable in servicing thousands of taxicabs across Europe in the 1950s and ’60s, and quite possibly is still in daily use in Cuba today. The block is made of cast iron, with the cylinder head and oil pan aluminum.
  • Parts: Parts from the Classic Center manufactured to original specifications, and aftermarket replacement parts, are readily available.


Reasons Not to Buy a W121

  • Rust: The main problem with the unibody 190SL, like 356 Porsches, is that it’s vulnerable to rust.
  • Previous poor body repairs: The 190SL depreciated to an average value of $2,000 to $4,000 by 1975. Few owners were prepared to spend $20,000 at a reputable shop to repair a $4,000 190SL. Most 190SLs have had older body repairs, many of which were poorly done. It’s better to buy a car with original unrepaired body panels, even with some rust, than one with badly repaired panels.
  • Restoration costs: The increasing cost of both NOS and reproduction parts results in high restoration costs.
  • Lack of power: The 190SL is underpowered for its weight.



Most 190SL cars will have some rust in the chassis and/or on the body. Due to double-wall construction and clogged drain holes, many of these cars rusted from the inside out. While rust is a serious problem with any older car, the 190SL, with its ’50s unibody construction, is particularly vulnerable. Buyers must be keenly aware of rust problems and walk away from any candidate exhibiting extensive rust, particularly in structural areas. Far and away, rust will become the most labor-intensive and expensive challenge to deal with after purchase.

Failure to notice evidence of extensive rust before purchase can result in major expense, but uncovering inferior accident or rust repair after purchase can seriously compound the mistake. To make matters worse, this inferior work is most likely hidden on an otherwise attractive car selling at a higher initial price. When evaluating a potential candidate for rust, it is important to have a long, thin screwdriver or awl for examination purposes. Typical areas that should be tested to determine the integrity of the metal include the fore and aft portions of the wheel wells, rockers (especially at the stone guard), chassis frame rails, mounting points for the rear trailing arms, trunk floors, and spare-tire wells. Floor panels are typically rusted, especially on the passenger floor, due to leaking battery acid from the engine compartment. Because problems with rust are so prevalent, one must be especially diligent to uncover previous attempts to fix such areas by replacing body panels (a seam in the front fender well at the light bucket indicates a poorly welded overlapping nose replacement), attempting bondo jobs, or, worse yet, masking the rust with undercoating. Equally dangerous is the pretty paint job, fresh kit interior, and reproduction top that divert your attention from the more rigorous task of probing for rust under the car.

The 190SL was built on an assembly line, but the car was still largely custom fit. Body panels were trimmed and fit to precise gaps. Chrome was tailored and fit to body panels. The dashboard and top were modified to fit tightly. These cars were the product of human hands, and no two were identical. As a consequence, the labor required to refit the car that does not have its original body panel and chrome components is a source of great expense when restoring or repairing. Due diligence in validating the completeness and originality of the car can minimize this expense. Fortunately, Mercedes-Benz made this task relatively easy. The doors, hood, trunk, and top bow, as well as other parts, were stamped with the body number of the car, or a portion of the body number, which is also found stamped into the firewall. Likewise, a grease pencil was used to mark the seats and other soft-good components with the same number. If you find matching numbers in several of these areas, chances are you have a fairly original candidate.

When initially evaluating a purchase, I like to look at the dates stamped on the wheel rims. If they all match, there’s a good chance the car is not a previous project car. Another test for originality is to obtain the data sheet or vehicle data card from the Irvine Classic Center and verify the numbers of the steering box, left and right front axles, rear axle, engine, and transmission. Original mechanical components offer another indication of the car’s history.

While originality is an important money saver with respect to the fit of the car, completeness is also a major cost factor. The expense of acquiring missing components adds up very quickly. Seemingly inexpensive items quickly become pricey. A 190SL original glove box Kienle clock, for example, has been reported to sell for $800 on eBay. Piece by piece, the items start to add up, and then there’s still the cost of refinishing the components to one’s standard.

Test-driving the car and having a knowledgeable source evaluate key components will help verify mechanical integrity. Audit specific items, including engine leakdown percentage and compression numbers, tightness of the front subassembly, rear axle noise, leaks, and brake-system condition. Do functions such as the lighting operate as the owner’s manual suggests? Do the radio, clock, and other instruments work correctly?

Achilles’ heels are few. The Solex carbs used to be widely condemned but are back in favor among the knowledgeable since quality rebuilds became available. Solex problems are mostly traceable to inadequate rebuilds and poor installation. Mercedes engineered these carbs to have two barrels active at low speeds, and four at 2,200 rpm, controlled by vacuum. Once set up, properly installed Solexes will last a number of years without retuning, offering better (and smoother) low- and mid-range power than Webers or Mikunis.

Braking systems are inherently excellent on these cars. When new, the cars would stop smoothly and quickly from highway speeds. I find them more than adequate for modern driving, but only if they are installed and adjusted correctly. If your prospective 190SL pulls right or left under braking, or if it has a low pedal engagement point, you have an adjustment or worn-parts problem.



Sept. 2, 1953Daimler-Benz Board of Management approves Max Hoffman’s request to build the 190SL.
Feb. 6, 1954International Auto Show, New York. The 190SL exhibition model and the 300SL Coupe first presented to the public.
Apr. 20, 1955First 190 SL rolled off the Sindelfingen production line.
July 20, 1955 ATE T50 brake booster available as an option.
Sept. 22, 1955 Solex carburetors changed from sand-cast to die-cast.
Oct. 28, 1955Transmission gear ratios changed from 3.4/2.0/1.29/1 to 3.52/2.32/1.52/1.
Dec. 5, 1955  Eyebrows (chrome strips) that are standard for the coupe since production available as an option for the roadster.
Jan. 12, 1956 Four-point engine suspension replaces the three-point.
Feb. 22, 1956Coupe hardtop made of aluminum metal changed to steel sheet metal .8mm thick.
Apr. 24, 1956 Coupe folding seats replaced the bucket seats in the roadster.
Apr. 28, 1956ATE T50 brake booster becomes standard equipment.
June 11, 1956Large taillights like the 220A & 220S installed.
July 23, 1957Rear license plate lights moved from the body to the bumper guards.
May 5, 1958Sun visors with leather covering replace the plexiglass style.
July 31, 1958Steering lock/ignition switch now standard production.
Oct. 9, 1959  Hardtop with large rear window installed.
Aug. 31, 1960Trunk handle changed to separate lock and handle.
Jan. 5, 1961Fuel tank becomes ventilated. Prior to this the fuel cap was ventilated.
Aug. 1, 1961928 engine introduced.
Feb. 8, 1963W121 production ceases.


Value Estimates – 190SL

Low:  $8,000-$20,000; Medium: $20,000-$60,000; High $60,000-$200,000.

Low estimates are for cars that can be driven safely but may have expensive-to-fix cosmetic issues. Medium values are for cars that could win local car shows. High values are for exceptional, rarely driven cars.

On the Market

Here are some real-world ads for 190SLs on the market at the time this article was written, as examples of availability and prices.

1956 Coupe $14,500 – Parts car, completely disassembled with various components in boxes. Floor-pan and body-panel rust. Requires complete restoration. Some parts are missing from the inventory. Hardtop and soft top included. Bumpers complete but in poor condition.

1958 Coupe $42,000 – Chassis No. 121 040 10 8501152, DB 050 White with Red leather interior. Includes hardtop. Convertible top restored three years ago. Mileage 96,114. New Weber DCOE 40 carburetors (three years old). New starter (two years old). One owner. Original maintenance records from purchase included.

1958 Roadster $69,000 – Chassis No. 121 042 10 85000250 – 73,500 miles, DB 180 G Silver Metallic with Red (Rot) leather interior. Restoration by Bruce L. Adams in 1994. This Mercedes-Benz 190SL comes fully restored and maintained to a high standard for the past 15 years. This is an exceptional car that can be enjoyed fully and driven away. The car was brought to original specifications in 2008 for driving enjoyment and appearance, as well as careful updating of certain components for improved drivability, safety, and handling. Engine bay has been detailed to good but not show standards. Undercarriage is excellent in original tan color; no undercoating. Car is equipped with 25mm sway bar, seat belts, Coco Mats, Kienle 7-day clock in working condition, jumpseat (third seat), Hirschmann antenna, Becker Europa Radio, square-weave carpet in excellent condition, and soft top in very nice condition in original Happich fabric.

1961 Coupe $72,500 – Chassis No. 121 042 10 – 16,592 miles, DB 40 G Black with Red (Rot) leather interior. One owner. 190SL in excellent original, unrestored condition, idles at 950; runs and starts well. Mileage documented as correct. Includes hardtop.

1960 Roadster $117,500 – Chassis No. 121 042 10 01875 – 682 miles following restoration, DB 180 G Silver Metallic with Red (Rot). A Bruce Adams restoration in 2000. The underside has the correct tan color, no undercoating, with the flexible additive added for longevity. The engine and drivetrain were fully rebuilt. It runs beautifully and still only has less than 700 miles. Concours-quality car.

For More Information

Mercedes-Benz 190SL 1955-1963 • Restoration and Ownership, Volume I. Bruce L. Adams. Published by the International 190SL Group. 2003. ISBN: 0-9729420-0-9

Mercedes-Benz 190SL 1955-1963 • Restoration and Ownership, Volume II. Bruce L. Adams. Published by the International 190SL Group. 2003. ISBN: 978-0-9729420-1-0

The SL Experience – Five Decades of the Mercedes-Benz SL (pp. 2-5 and 52-66). John R. Olson. Published by SL Market Letter. 2001. ISBN: 0-9635394-2-6.


Weights and Measures

Battery: 12-V, 56 Ah

Generator: 160 W

Wheelbase: 94.5 in

Track, front/rear: 56.7 /58.4 in

Ground Clearance: 6.1 in

Overall Length: 168.9 in

Width:  68.5 in

Height:  52.0 in

Curb Weight: 2,557 lb; hardtop add 44 lb           

Wheels:  Steel 5 x13in

Tires: 6.40 x 13in

0-60mph: 13.2 sec

Standing 1/4 mile: 19 sec

MPH at 1/4 mile: 75 mph

Max Speed: 105 mph            

Fuel economy: 18.8 to 25mpg

Fuel capacity: 17gal - 96 octane (premium leaded)


Technical Specifications

Engine No. Prefix:M121BII

Engine type:

Four-stroke 4-cylinder inline overhead cam

three main bearing crankshaft

Bore & Stroke:85 x 83.6 mm
Compression ratio:

8.5:1 to engine no. 65.03803 – 1956

8.8:1 after engine no.65.03804

8.7:1 with 121.928 engine adopted summer 1961

Max power:DIN 105 hp at 5,700 rpm, 120 hp SAE
Max torque:114 lb-ft at 3,200 rpm
Valve drive:Overhead camshaft (duplex chain)
Cooling:Water with pump 10.5 qt circulating
Lubrication:Pressure circulation 4.24 qt capacity
Fuel system:

Two Solex horizontal dual 44 PHH carburetors

Vacuum-controlled second stage

Transmission:4-gear manual constant synchromesh in ATF fluid

1st version up to Nov 11, 1955

I  3.40 / II  2.00 / III  1.29 / IV 1.00 / R  3.29;

then: I  3.52 / II 2.32 / III 1.52 / IV 1.00 / R 3.29


Single plate, dry

Rear axle ratio:

3.70:1 up to chassis no. 5500060, April 29, 1955

3.89:1  2nd version up to Sept 27, 1955

3.90:1  3rd version after 5500061, except 5500051 to 5500056 and 5500058

4.10:1 ratio was available on special request

Drive shaft:Power transmission to rear wheels by half-shafts
Suspension-front:Independent suspension with dual wishbone, coil springs, and 20mm stabilizer  
Suspension-rear end:Single pivot swing axle with trailing arms, coil springs
Shock absorbers:Hydraulic telescopic

Recirculating ball 18.5:1 with steering damper

3.5 revolutions from stop to stop

Brakes:Hydraulic drum brakes, 9.1 in diameter,
front duplex operation. ATE T 50 servo booster
first optional, then standard from April 1956)
Hand brake:Cable located on rear left wheel
Body structure:Unibody – Sheet steel welded to frame/floor-pan unit; aluminum doors and lids


Production Numbers

The 190SL was usually titled in the particular year sold, regardless of year of manufacture. Production changes were numerous through out the nine years of manufacturing, resulting in changes recorded by DBAG using chassis and/or engine numbers.

190SL Production Table

YearNon-USAUSATotalChassis Numbers*

95.00001-95.02398  to July

10.014211-10.015762  August on

Total155131036825881Total Export Units: 20,636


*Note that from 1955 to 1959 the chassis number begins with the last two digits of the calendar year in reverse. In July/August 1959, DBAG adopted a new numbering scheme. The serial number now became the cumulative production number of the car. Also note that discrepancies in production figures vs. chassis numbers arise due to different record keeping (production versus actual sales) and because 190SLs not sold by DBAG could be held in the factory in December for a next-year delivery.