Buyers Guide – Overlooked Treasures; The W108-W109 250, 280 & 300 Series • 1965-1972

Richard Simonds, Data Daniel Stahl

BUYERS GUIDE 01.jpgWriting in Road & Track magazine, the great automotive journalist Tom McCahill identified the mighty Mercedes-Benz 300SEL 6.3 as “Merely the greatest sedan in the world.” The 300SEL 6.3 was also considered “The Gentleman’s Hot Rod” at the time. Even the basic W108 250S sedan was singled out: “The near-perfect mating of suspension, brakes, power plant and functional design makes it one of the most desirable ‘sports sedans’ in the world.”


Buyers Guide

Overlooked Treasures

The W108-W109 250, 280 & 300 Series • 1965-1972





Writing in Road & Track magazine, the great automotive journalist Tom McCahill identified the mighty Mercedes-Benz 300SEL 6.3 as “Merely the greatest sedan in the world.” The 300SEL 6.3 was also considered “The Gentleman’s Hot Rod” at the time. Even the basic W108 250S sedan was singled out: “The near-perfect mating of suspension, brakes, power plant and functional design makes it one of the most desirable ‘sports sedans’ in the world.”

Following up on the W110-W111 series Finback sedans, the design of the W108 included unibody construction with “safety zones” designed to crumple on impact, a padded dash, seat belts, headrests, recessed door handles, a collapsible steering column mounted behind the front axle rather than in front of it, and a spring-mounted rearview mirror designed to break away if struck. In 2010, the authoritative website referred to the model range as: “The 108 chassis: the perfect entry level classic Mercedes.”

The short-wheelbase models had a 108.3-inch wheelbase; the SEL models stretched out to a 112.2-inch wheelbase. The W108 series had coil springs; the W109 had air suspension. Offering several different engines over the production run, the sedans were available in 250, 280 and 300 versions with in-line 6-cylinder engines and 3.5L, 4.5L and 6.3L V-8 engines. Today, the 108 and 109 series sedans could be called “The Forgotten Generation.” Current books and buyers’ guides emphasize the coupes, cabriolets and SLs and, with the exception of the 300SEL 6.3s, ignore these magnificent and practical sedans, making them much less expensive than other classic Mercedes-Benz automobiles and thus even better for the beginning classic-car enthusiast.



The W108-W109 series was developed to bring a larger and more contemporary style to the lineup of Mercedes-Benz sedans. Visibility is very good. Paul Bracq’s styling remains timeless, and few people recognize the car as being a 50-year-old design. The trunks were larger, the wheels were 14 inch (instead of 13 inch), the engines were more powerful, and the driver and passenger amenities were more in line with cars of the 1960s than previous-generation Mercedes-Benz sedans. Four-wheel disc brakes were standard. Air conditioning was mounted under the dash, but was not known for being effective in temperatures above 85F. Seat belts were standard, although fitted with Kangol magnetic buckles that seem quirky by today’s safety standards.

Virtually all vehicles coming to the United States had automatic transmissions; the 4-speed manual transmissions with a column-mounted or floor-mounted shifter was an option on all models except the 4.5- and 6.3-liter V-8s. A 5-speed manual transmission with a floor-mounted shift lever was available on the 300SE, 300SEL 3.0 and 2.8, 250SE, 280SE and 280SEL equipped with the inline six-cylinder engines.

Total production worldwide of the various W108-W109 models was 383,341 from 1965 to 1972. The range could be considered a success by the fact of that volume alone. This also means that there is a potentially large pool from which to select a pristine example. Remember the adage, “Always buy the best example you can find.” In general, full restoration is always more costly than the ultimate value of these vehicles


Why to buy a W108-W109

Engineering and build quality were excellent. Safety features make the W108-W109 an exceptional family car for daily use. Styling is contemporary and classic at the same time. These models can comfortably haul five people and their “stuff” on trips. Parts (new, used, and remanufactured) are generally available for W108-W109 bodies, engines, drivetrains, etc. Air suspension on the W109 series offers a supple ride with great handling and control. The model range was built with a variety of engines, so you have many choices.


Why not to buy a W108-W109

Sedans often suffer from neglected servicing and components that need rebuilding or replacement. Bosch D-Jetronic fuel-injection systems on 3.5- and 4.5-liter V-8 engines are expensive to repair or rebuild. Faulty steering boxes and automatic transmissions are expensive to replace. Fuel-system components (from fuel tanks to fuel pumps to carburetors to injection systems) may need rebuilding or replacement due to damage from ethanol fuel additives – particularly a risk for a car that has been stored for years. All W108-W109s require premium fuel, although unleaded fuel is not a problem because Mercedes-Benz used hardened valves and valve seats on all models by 1951. Automatic transmissions may shift harshly and must be properly serviced to assure longer life and smoother shifting. Door-lock systems, window regulators, window-channel materials and power-window switches may need to be rebuilt or replaced.



Chassis – Although the factory touted its “heavy slathering of plasticized undercoating,” rust is always a major issue, especially with front frame rails and bumper supports because of their structural importance. In addition, floor pans, fenders, door rocker panels and doorsills need to be checked.

Engine – Most of these lower-priced examples have been just “old cars” for a long time, purchased by people who might not have had the money or time to invest in engine maintenance. Engine bearings, camshafts, and other moving parts can suffer from postponed oil changes or oil with the improper lubricity classifications. Have the engine checked out thoroughly by an experienced Mercedes-Benz mechanic with the proper equipment to avoid expensive surprises that can double or triple the price you pay for the car. Pay particular attention to the fuel system, as noted below.

Suspension linkages – These cars have lubrication points throughout the suspension and lack of regular maintenance can allow the grease to solidify into a concrete-like consistency, causing damage to lower control arms, suspension links, kingpins and dried-out bushings that need to be replaced. The early cars had a hydraulic compensator on the rear suspension. If it fails, it can also damage axle boots.

Air suspension – Repairing the air suspension system of a neglected car may be very costly. Air suspension on all 109 models requires regular maintenance and the use of methanol-based antifreeze to avoid water in the air lines. Check for damage to the air valves, air lines, pump and air bags. A well-maintained air suspension should hold air without leaking and stay inflated for two weeks. The 109 series with air suspension are: 300SEL; 300SEL 3.5; 300SEL 4.5; 300SEL 6.3. The 280SELs were not available with air suspension.

Differential – Bearing noise and gear-lash adjustments are the most likely culprits here. Bearings may need to be replaced. The 6.3 models are vulnerable to differential wear and stripped pinion gears because of overly enthusiastic driving. “But, Dad, the 6.3 has so much torque! I had to test its performance.”

Interior – Heater-blower motors and bronze bearings are inaccessible and quite expensive to replace. Heater-control levers can be easily replaced, although the underlying problem of poor access to lubricate the controls and cables is an issue for all Mercedes-Benz vehicles of this vintage. Power-window switches may need to be rebuilt (see article in The Star, July-August 2008, pp. 76-80). M-B Tex (bonded vinyl) is nearly indestructible, but back-seat upholstery may dry out from sun exposure coming in the back window. Carpeting wears out, although complete color-matched kits are available from several sources. The woodwork on the dash is not as finely finished as in other models and may need to be refinished or replaced.

Gearbox – Automatic transmissions are fairly durable, but often need a rebuild kit for vacuum modulators. These are fairly basic, mechanically operated units that are durable if serviced regularly. For the column-shift, check the cable-driven shift indicator for adjustment or replacement and general wear in the shift linkages and bushings to the transmission.

Fuel System (carburetors or fuel injection) – Poorly maintained carburetors and fuel-injection system necessitate rebuilding, although the basic components are quite durable and don’t often need to be replaced.

Power Steering – Power-steering pumps and reservoirs may need rebuilding and hoses replaced.

History – Get as much information as you can about the vehicle you are interested in from the seller, including history of maintenance as far back as you can get it. These vehicles are well engineered and quite durable, but the 6-cylinder engines will likely need a rebuild around 200,000 miles, while V-8 engines are probably good for 300,000 miles.



A well-chosen example of any of the many models from the W108-W109 range can offer the canny Mercedes-Benz enthusiast that rarest of opportunities in today’s heavily scrutinized classic-car marketplace: an elegant, timeless example of a high-quality automobile from a seminal period in the company’s history available at a comparatively modest price.




With strong unibody construction (1)


underpinning Paul Bracq’s elegant design, plus the latest in driver and passenger comfort and safety features (2),


including a carefully designed ventilation system (3)


and fully adjustable ergonomic seating (4),


the W108 quickly became a sales success for Mercedes-Benz.


Fitted with the powerful V-8 engine (5),


automatic gearbox and air suspension from the firm’s top-of-the line 600 model, the W109 300SEL 6.3 (6) created a sensation when introduced to the public in March 1968 at the Geneva Motor Show.





1965    August            Introduction of the W208 250S, 250SE and 300SE with 

                                    conventional suspension and SWB

1966    March             W109 300SEL introduced with long wheelbase and air suspension

1967    November      280S introduced with improved 7-main-bearing engine with
                                   redesigned cylinders and head

1967    December      300-hp V-8 300SEL 6.3 introduced

1968    January          280SE and 280SEL introduced; 250S and SE soon discontinued

1968    January          W111 Finback range discontinued, having overlapped the W108-
                                   W109 for three years

1969    August           W109 300SEL 3.5 introduced, replacing 2.8-liter 300SEL

1971    March             280SE 3.5 and 280SEL 3.5 introduced, 1 280SEL soon discontinued

1971    May                 280SE/SEL 4.5 and 300SEL 4.5 introduced as U.S.-only models

1972    November      The entire W108-W109 range discontinued


SPECIFICATIONS: Mercedes-Benz W108-W109 Sedans – 1965-1972


MODEL           YEARS        CHASSIS              ENGINE                  HORSEPOWER      TORQUE                                   

250S            1965-1969       108.012        2.5L I-6 OHC 108.920            146                    157                                         

250SE          1965-1968       108.014       2.5L I-6 OHC 129.980            170                     174                                         

300SE          1965-1967       108.015       3.0L I-6 OHC 189.989            195                     203                                         

300SEL        1966-1967       109.015       3.0L I-6 OHC 189.988            195                     203                                         

300SEL         1968-1970      109.016       2.8L I-6 OHC 130.981            195                     195                                         

300SEL 6.3   1968-1972      109.018       6.3L V-8 OHC 100.981           300                     434                                         

280S             1968-1972      108.016       2.8L I-6 OHC 130.920            157                     181                                         

280SE/280SEL 1968-1972  108.018/.019   2.8L I-6 OHC 130.980        180                     193                                         

300SEL 3.5       1969-1972  109.056      3.5L V-8 OHC 116.981             230                    231                                         

280SE/SEL 3.5 1971-1972   108.057/.058  3.5L V-8 OHC 116.980        230                    231                                         

280SE/SEL 4.5 1971-1972   108.067/.068  4.5L V-8 OHC 117.984         230                  278                                         

300SEL 4.5      1971-1972    109.057      4.5L V-8 OHC 117.981            230                   278                                         



                       TRANSMISSION   REAR AXLE        0-62         TOP SPEED                 MPG

250S                4-A                                 3.92             14 sec        110                            13.7

250SE             4-A                                 3.92             13 sec         117                            13.7

300SE             4-A                             3.92/3.69         12 sec        115, 121                     12.3/13.7 

300SEL           4-A                             3.92/3.69         12 sec        115, 121                     12.3/13.7

300SEL           4-A                                 4.08             11.5 sec      118                            13.4

300SEL 6.3     4-A                                 2.85                6.5 sec     137                            11.2

280S               4-A                                 4.08                12.5 sec    112                            16

280SE/280SEL  4-A                              4.08                0.5 sec                                       115                                        16

300SEL 3.5                           4-A                                 3.69                                              9.5 sec                                         127                                      12.7

280SE/SEL 3.5                  4-A                                 3.69                                               10 sec                                          124                                      12.7

280SE/SEL 4.5                  3-A                                 3.23                                               12 sec                                          118                                        16

300SEL 4.5                           3-A                              3.23                                                12 sec                                          118                                         16


Production Totals

250S                            74,677

250SE                          55,181

300SE/SEL/SEL 2.8     2,737/2,369/2,519

300SEL 6.3                  6,526

280S                            93,935

280SE/SEL                   91,051/8,250

300SEL 3.5                  9,583

280SE/SEL 3.5             11,309/951

280SE/SEL 4.5             13,527/8,173

300SEL 4.5                  2,553

TOTAL                         383,341