The Mercedes-Benz W123 represents a pivotal era for the German automaker, solidifying its reputation for building durable, comfortable, and safe mid-size automobiles. Produced from September 1979 to December 1985, the W123 succeeded the W114 and W115 models and was itself replaced by the W201 (190E). This generation saw significant advancements in engineering and safety features, becoming a popular choice for families and executives alike, particularly in Europe where it was a common sight on the roads. While not initially a major seller in the United States due to emissions regulations and a preference for larger American cars, the W123 has gained a dedicated following among enthusiasts for its build quality and classic styling.
Mercedes-Benz W123 250: A Detailed Overview
The W123 was offered in a variety of body styles, including sedan, coupe (C123), station wagon (S123), and limousine. The 250 model, equipped with a 2.5-liter inline-six engine, occupied a sweet spot in the range, offering a balance of performance and fuel efficiency. This model was particularly popular in European markets, where it was seen as a refined and capable touring car. The W123’s design emphasized practicality and understated elegance, a hallmark of Mercedes-Benz during this period.
Engine & Performance
The heart of the W123 250 is its M 123 V 25 / 123.921 2.5-liter inline-six cylinder engine. This naturally aspirated engine produces 140 horsepower at 5500 rpm and 200 Nm (147.51 lb.-ft.) of torque at 3500 rpm. The engine features a single overhead camshaft (SOHC) valvetrain and utilizes a carburetor fuel injection system, a common technology for the time. Power is delivered to the rear wheels via a four-speed automatic transmission. Acceleration from 0 to 60 mph takes approximately 11.6 seconds, while 0 to 100 km/h is achieved in 12.2 seconds. The W123 250 boasts a top speed of 180 km/h (111.85 mph). The engine’s power-to-weight ratio is 99.3 HP per tonne, and the torque-to-weight ratio is 141.8 Nm per tonne. The engine displacement is 2525 cm3 (154.08 cu. in.), and the compression ratio is 9:1.
Design & Features
The W123 is a four-door sedan with a classic three-box design. Its exterior is characterized by clean lines, a relatively upright grille, and prominent headlights. The interior is spacious and well-appointed, offering comfortable seating for five passengers. The W123 was notable for its focus on safety, incorporating features such as crumple zones, reinforced passenger cell construction, and anti-lock braking systems (ABS) – a relatively new technology at the time. The car’s suspension utilizes a double wishbone setup at the front and a trailing arm configuration at the rear, providing a comfortable ride. Disc brakes are fitted on all four wheels. The W123’s build quality is renowned, with a focus on durability and longevity. Features like power windows and central locking were available, depending on the trim level and market. The fuel tank capacity is 80 liters (21.13 US gal | 17.6 UK gal).
Technical Specifications
| Brand | Mercedes-Benz |
| Model | W123 |
| Generation | W123 |
| Type (Engine) | 250 (140 Hp) Automatic |
| Start of production | September, 1979 |
| End of production | December, 1985 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Sedan |
| Seats | 5 |
| Doors | 4 |
| Fuel consumption (urban) | 16 l/100 km (14.7 US mpg, 17.7 UK mpg, 6.3 km/l) |
| Fuel consumption (extra urban) | 10.1 l/100 km (23.3 US mpg, 28 UK mpg, 9.9 km/l) |
| Fuel Type | Petrol (Gasoline) |
| Acceleration 0 – 100 km/h | 12.2 sec |
| Acceleration 0 – 62 mph | 12.2 sec |
| Acceleration 0 – 60 mph | 11.6 sec |
| Maximum speed | 180 km/h (111.85 mph) |
| Weight-to-power ratio | 10.1 kg/Hp |
| Weight-to-torque ratio | 7.1 kg/Nm |
| Power | 140 Hp @ 5500 rpm |
| Power per litre | 55.4 Hp/l |
| Torque | 200 Nm @ 3500 rpm (147.51 lb.-ft. @ 3500 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | M 123 V 25 / 123.921 |
| Engine displacement | 2525 cm3 (154.08 cu. in.) |
| Number of cylinders | 6 |
| Engine configuration | Inline |
| Cylinder Bore | 86 mm (3.39 in.) |
| Piston Stroke | 72.45 mm (2.85 in.) |
| Compression ratio | 9:1 |
| Number of valves per cylinder | 2 |
| Fuel injection system | Carburettor |
| Engine aspiration | Naturally aspirated engine |
| Valvetrain | SOHC |
| Engine oil capacity | 7.5 l (7.93 US qt | 6.6 UK qt) |
| Coolant | 10 l (10.57 US qt | 8.8 UK qt) |
| Kerb Weight | 1410 kg (3108.52 lbs.) |
| Max. weight | 1930 kg (4254.92 lbs.) |
| Max load | 520 kg (1146.4 lbs.) |
| Fuel tank capacity | 80 l (21.13 US gal | 17.6 UK gal) |
| Length | 4725 mm (186.02 in.) |
| Width | 1786 mm (70.31 in.) |
| Height | 1438 mm (56.61 in.) |
| Wheelbase | 2795 mm (110.04 in.) |
| Front track | 1488 mm (58.58 in.) |
| Rear track | 1446 mm (56.93 in.) |
| Drivetrain Architecture | Rear wheel drive |
| Number of gears and type of gearbox | 4 gears, automatic transmission |
| Front suspension | Double wishbone |
| Rear suspension | Trailing arm |
| Front brakes | Disc |
| Rear brakes | Disc |
| Steering type | Cone worm with recirculation balls |
| Wheel rims size | Front wheel rims: 5.5J x 14Rear wheel rims: 5.5J x 14 |
The Mercedes-Benz W123 250 remains a highly regarded classic car, appreciated for its robust engineering, comfortable ride, and timeless design. Its enduring popularity is a testament to the quality and foresight of Mercedes-Benz during this era of automotive history.
