The Mercedes-Benz W123, produced from July 1975 to August 1978, represents a pivotal generation in the lineage of the iconic Mercedes-Benz E-Class. Positioned as a mid-size luxury sedan, the W123 succeeded the W114 and W115 models, establishing a new benchmark for safety, build quality, and refinement in its segment. The 240 D variant, powered by a 2.4-liter diesel engine, was a particularly popular choice, especially in Europe, where diesel fuel was more affordable and readily available. This model offered a blend of fuel efficiency and the renowned Mercedes-Benz driving experience.
The Mercedes-Benz W123 240 D: A Legacy of Engineering
The W123 series was a significant departure from its predecessors, incorporating advancements in crumple zone technology and overall structural integrity. It was designed with a focus on passenger safety, a relatively new priority in automotive engineering at the time. The 240 D, while not the most powerful version of the W123, was celebrated for its durability and longevity, becoming a common sight on European roads for decades. Its robust diesel engine and simple, yet effective, mechanical design contributed to its reputation for reliability. The W123 was never officially sold in the United States with a diesel engine due to increasingly stringent emissions regulations.
Engine & Performance
The heart of the W123 240 D is the OM 616 D 24 engine, a 2.4-liter (146.7 cubic inches) inline-four cylinder diesel. This naturally aspirated engine produces 65 horsepower at 4200 rpm and 137 Nm (101.05 lb.-ft.) of torque at 2400 rpm. While the horsepower figure may seem modest by modern standards, the engine’s torque characteristics provide ample pulling power for comfortable cruising. The engine utilizes precombustion chamber injection, a common diesel technology of the era, to improve combustion efficiency. Power delivery is managed through a four-speed automatic transmission, driving the rear wheels. Acceleration from 0 to 100 km/h (0-62 mph) takes approximately 27.4 seconds, and the vehicle reaches a maximum speed of 133 km/h (82.64 mph). The weight-to-power ratio is 21.5 kg/Hp, and the weight-to-torque ratio is 10.2 kg/Nm.
Design & Features
The W123 240 D is a four-door sedan with a classic, understated design. Its body style is characterized by clean lines, a relatively upright stance, and a prominent grille with the iconic Mercedes-Benz three-pointed star. The interior is functional and well-appointed, reflecting the luxury aspirations of the era. The vehicle comfortably seats five passengers. Safety features, while limited by the standards of today, were advanced for the mid-1970s and included a reinforced passenger cell and crumple zones designed to absorb impact energy. The suspension system utilizes a double wishbone setup at the front and a trailing arm configuration at the rear, providing a comfortable ride. Braking is handled by disc brakes on all four wheels. The steering system employs a cone worm with recirculation balls, offering precise control. The 240 D’s design prioritized practicality and durability, making it a popular choice for families and long-distance travelers.
Technical Specifications
| Brand | Mercedes-Benz |
| Model | W123 |
| Generation | W123 |
| Type (Engine) | 240 D (65 Hp) Automatic |
| Start of production | July, 1975 |
| End of production | August, 1978 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Sedan |
| Seats | 5 |
| Doors | 4 |
| Fuel consumption (urban) | 9.5 l/100 km (24.8 US mpg) |
| Fuel consumption (extra urban) | 8.1 l/100 km (29 US mpg) |
| Fuel Type | Diesel |
| Acceleration 0 – 100 km/h | 27.4 sec |
| Acceleration 0 – 62 mph | 27.4 sec |
| Acceleration 0 – 60 mph | 26 sec |
| Maximum speed | 133 km/h (82.64 mph) |
| Weight-to-power ratio | 21.5 kg/Hp |
| Weight-to-torque ratio | 10.2 kg/Nm |
| Power | 65 Hp @ 4200 rpm |
| Power per litre | 27 Hp/l |
| Torque | 137 Nm @ 2400 rpm (101.05 lb.-ft. @ 2400 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | OM 616 D 24 / 616.912 |
| Engine displacement | 2404 cm3 (146.7 cu. in.) |
| Number of cylinders | 4 |
| Engine configuration | Inline |
| Cylinder Bore | 91 mm (3.58 in.) |
| Piston Stroke | 92.4 mm (3.64 in.) |
| Compression ratio | 21.5:1 |
| Number of valves per cylinder | 2 |
| Fuel injection system | Precombustion chamber injection |
| Engine aspiration | Naturally aspirated |
| 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 | 1395 kg (3075.45 lbs.) |
| Max. weight | 1915 kg (4221.85 lbs.) |
| Max load | 520 kg (1146.4 lbs.) |
| Fuel tank capacity | 65 l (17.17 US gal | 14.3 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 | 4 |
| Gearbox type | 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 | 5.5J x 14 |
The Mercedes-Benz W123 240 D remains a highly regarded classic car, appreciated for its robust engineering, comfortable ride, and timeless design. It represents a significant milestone in the evolution of the Mercedes-Benz brand and continues to be a popular choice among enthusiasts and collectors worldwide.
