The Mercedes-Benz W123, produced from 1976 to 1985, represents a pivotal generation in the lineage of the Mercedes-Benz E-Class. Specifically, the 240 D model, powered by a 2.4-liter diesel engine producing 72 horsepower, was a cornerstone of the W123’s success, particularly in Europe where diesel engines were favored for their fuel efficiency. The W123 was lauded for its robust build quality, engineering refinement, and safety features, establishing a new benchmark for mid-size luxury vehicles. It remains a highly sought-after classic car, appreciated for its durability and timeless design.
The Mercedes-Benz W123 240 D: A Detailed Overview
The W123 series succeeded the W114 and W115 models, and was available in saloon (sedan), coupé, and estate (wagon) body styles. The 240 D, introduced in August 1978, quickly became a popular choice due to its fuel economy and reliability. It was designed to appeal to buyers seeking a comfortable, well-engineered vehicle capable of handling long distances. While not initially sold in significant numbers in the United States (diesel emissions regulations played a role), the W123 gained a strong following among enthusiasts who appreciated its understated elegance and mechanical simplicity.
Engine & Performance
The heart of the 240 D is the OM 616 D 24 engine, a 2.4-liter (2399 cm3 or 146.4 cu. in.) inline-four cylinder diesel. This engine, known for its longevity, produces 72 horsepower at 4400 rpm and 137 Nm (101.05 lb.-ft.) of torque at 2400 rpm. The engine utilizes precombustion chamber injection, a common diesel technology of the era, to improve combustion efficiency. While acceleration is modest – 0 to 100 km/h (0-62 mph) takes approximately 24.6 seconds, and 0 to 60 mph is achieved in around 23.4 seconds – the 240 D was not designed for outright speed. Instead, it prioritized fuel efficiency and durability. Fuel economy figures are impressive for its time, achieving approximately 9.5 l/100 km (24.8 US mpg) in urban driving and 7.2 l/100 km (32.7 US mpg) on the open road. The engine’s longitudinal front-engine layout and rear-wheel drive configuration contribute to its balanced handling characteristics.
Design & Features
The W123 240 D is a four-door sedan seating five passengers. Its design is characterized by clean lines, a relatively upright stance, and a focus on practicality. The body’s construction emphasized safety, incorporating crumple zones and a robust passenger cell. Compared to earlier Mercedes-Benz models, the W123 featured improved ventilation and heating systems, enhancing passenger comfort. Interior appointments, while not lavish, were well-executed with durable materials and a functional layout. Features like power-assisted disc brakes on all four wheels, a four-speed manual transmission, and a double wishbone front suspension and trailing arm rear suspension contributed to a comfortable and controlled driving experience. The car’s dimensions are substantial for its class, measuring 4725 mm (186.02 in.) in length, 1786 mm (70.31 in.) in width, and 1438 mm (56.61 in.) in height. The wheelbase is 2795 mm (110.04 in.).
Technical Specifications
| Brand | Mercedes-Benz |
| Model | W123 |
| Generation | W123 |
| Type (Engine) | 240 D (72 Hp) |
| Start of production | August, 1978 |
| End of production | November, 1985 |
| 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) | 7.2 l/100 km (32.7 US mpg) |
| Fuel Type | Diesel |
| Acceleration 0 – 100 km/h | 24.6 sec |
| Acceleration 0 – 62 mph | 24.6 sec |
| Acceleration 0 – 60 mph | 23.4 sec |
| Maximum speed | 143 km/h (88.86 mph) |
| Weight-to-power ratio | 19.4 kg/Hp |
| Weight-to-torque ratio | 10.2 kg/Nm |
| Power | 72 Hp @ 4400 rpm |
| 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 | 2399 cm3 (146.4 cu. in.) |
| Number of cylinders | 4 |
| Engine configuration | Inline |
| Cylinder Bore | 90.9 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 | 8 l (8.45 US qt | 7.04 UK qt) |
| Coolant capacity | 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 | Rear wheel drive |
| Number of gears | 4 |
| Gearbox type | Manual 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 testament to German engineering prowess. Its blend of durability, fuel efficiency, and understated luxury cemented its place as a classic, and continues to attract enthusiasts worldwide. Its robust design and relatively simple mechanics make it a rewarding vehicle for restoration and ownership, offering a glimpse into a bygone era of automotive engineering.
