The Mercedes-Benz W124, produced from 1985 to 1996, represented a significant leap forward in engineering and design for the German automaker. The facelifted version introduced in 1989 brought subtle but important refinements to the already highly regarded platform. Among the variants offered was the 300 D CAT 4MATIC, a diesel-powered sedan equipped with all-wheel drive. This model, produced between September 1989 and June 1991, catered to buyers seeking a blend of fuel efficiency, robust performance, and all-weather capability. While not initially a large seller in the United States, the W124 established Mercedes-Benz as a benchmark for quality and durability in the mid-size luxury segment, and continues to be a popular classic among enthusiasts.
Mercedes-Benz W124 300 D CAT 4MATIC: An Overview
The W124 series was designed as a successor to the W201 (190E) and W123 models, aiming to offer a more modern and refined experience. The 300 D CAT 4MATIC specifically combined the fuel economy and torque characteristics of a diesel engine with the added traction of Mercedes-Benz’s 4MATIC all-wheel-drive system. The “CAT” designation refers to the catalytic converter, implemented to meet increasingly stringent emissions regulations. This model was primarily sold in Europe, where diesel engines were – and continue to be – far more prevalent than in North America. It offered a practical and sophisticated option for drivers needing a reliable vehicle capable of handling diverse road conditions.
Engine & Performance
The heart of the 300 D CAT 4MATIC is the OM 603 D 30 inline-six cylinder diesel engine, displacing 2.996 liters (182.83 cubic inches). This engine produced 110 horsepower at 4600 rpm and 191 Nm (140.87 lb-ft) of torque between 2800 and 3050 rpm. While the horsepower figure might seem modest by modern standards, the engine’s strength lay in its substantial low-end torque, making it well-suited for hauling passengers and navigating challenging terrain. The engine utilized precombustion chamber injection, a technology common in Mercedes-Benz diesels of the era, for efficient combustion and reduced emissions. Power is delivered to all four wheels through a five-speed manual transmission. Acceleration from 0 to 100 km/h (0-62 mph) took approximately 15 seconds, with a top speed of 183 km/h (113.71 mph). The weight-to-power ratio of 14.3 kg/Hp and weight-to-torque ratio of 8.2 kg/Nm highlight the engine’s ability to move the vehicle despite its considerable weight.
Design & Features
The W124 300 D CAT 4MATIC is a four-door sedan with a classic, understated Mercedes-Benz design. The 1989 facelift brought minor cosmetic updates, including revised front and rear fascias, and updated interior trim. The body’s design prioritized aerodynamic efficiency and passenger safety. The interior was characterized by high-quality materials and a focus on comfort. Key features included hydraulic power steering, ventilated front disc brakes, and disc brakes on the rear axle. The 4MATIC system employed an electrically or mechanically operated clutch to engage the front wheels when rear wheel slip was detected, providing enhanced traction in slippery conditions. The inclusion of ABS (Anti-lock Braking System) was a significant safety feature for the time, helping to maintain steering control during emergency braking. The vehicle offered seating for five passengers and a generous 70-liter (18.49 US gallon) fuel tank, providing a substantial driving range.
Technical Specifications
| Brand | Mercedes-Benz |
| Model | W124 |
| Generation | W124 (facelift 1989) |
| Type (Engine) | 300 D CAT (110 Hp) 4MATIC |
| Start of production | September, 1989 |
| End of production | June, 1991 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Sedan |
| Seats | 5 |
| Doors | 4 |
| Fuel consumption (urban) | 10.6 l/100 km (22.2 US mpg / 26.6 UK mpg / 9.4 km/l) |
| Fuel consumption (extra urban) | 6.1 l/100 km (38.6 US mpg / 46.3 UK mpg / 16.4 km/l) |
| Fuel Type | Diesel |
| Acceleration 0 – 100 km/h | 15 sec |
| Acceleration 0 – 62 mph | 15 sec |
| Acceleration 0 – 60 mph | 14.3 sec |
| Maximum speed | 183 km/h (113.71 mph) |
| Weight-to-power ratio | 14.3 kg/Hp |
| Weight-to-torque ratio | 8.2 kg/Nm |
| Power | 110 Hp @ 4600 rpm |
| Power per litre | 36.7 Hp/l |
| Torque | 191 Nm @ 2800-3050 rpm (140.87 lb.-ft. @ 2800-3050 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | OM 603 D 30 / 603.912 |
| Engine displacement | 2996 cm3 (182.83 cu. in.) |
| Number of cylinders | 6 |
| Engine configuration | Inline |
| Cylinder Bore | 87 mm (3.43 in.) |
| Piston Stroke | 84 mm (3.31 in.) |
| Compression ratio | 22:1 |
| Number of valves per cylinder | 2 |
| Fuel injection system | Precombustion chamber injection |
| Engine aspiration | Naturally aspirated engine |
| Valvetrain | SOHC |
| Engine oil capacity | 7.5 l (7.93 US qt | 6.6 UK qt) |
| Coolant | 9 l (9.51 US qt | 7.92 UK qt) |
| Kerb Weight | 1570 kg (3461.26 lbs.) |
| Max. weight | 2090 kg (4607.66 lbs.) |
| Max load | 520 kg (1146.4 lbs.) |
| Fuel tank capacity | 70 l (18.49 US gal | 15.4 UK gal) |
| Length | 4740 mm (186.61 in.) |
| Width | 1740 mm (68.5 in.) |
| Height | 1450 mm (57.09 in.) |
| Wheelbase | 2800 mm (110.24 in.) |
| Front track | 1501 mm (59.09 in.) |
| Rear track | 1491 mm (58.7 in.) |
| Drivetrain Architecture | All wheel drive (4×4). ICE drives rear wheels, front wheels engaged via clutch. |
| Number of gears and type of gearbox | 5 gears, manual transmission |
| Front suspension | Wishbone |
| Rear suspension | Independent multi-link suspension |
| Front brakes | Ventilated discs |
| Rear brakes | Disc |
| Assisting systems | ABS (Anti-lock braking system) |
| Steering type | Cone worm with recirculation balls |
| Power steering | Hydraulic Steering |
| Tires size | Front/Rear: 195/65 R15 |
| Wheel rims size | Front/Rear: 6.5J x 15 |
The Mercedes-Benz W124 300 D CAT 4MATIC represents a high point in German engineering, offering a compelling combination of durability, efficiency, and all-weather capability. Its robust construction and relatively simple mechanicals have contributed to its enduring popularity among classic car enthusiasts, ensuring its place in automotive history.


