The Mercedes-Benz S 420, part of the W140 generation S-Class produced from 1994 to 1995, represented a significant evolution in luxury automotive engineering. Positioned as a mid-to-upper tier offering within the W140 range, it slotted between the S320 and the flagship S500 models. The W140 S-Class, known for its robust build quality and advanced features for its time, aimed to solidify Mercedes-Benz’s reputation for providing the ultimate in automotive comfort and technology. The facelifted models, like the S 420, addressed some initial criticisms regarding styling and offered refinements to the already sophisticated platform, the 1HX0 chassis.
Technical Specifications
| Brand | Mercedes-Benz |
| Model | S-class |
| Generation | S-class (W140, facelift 1994) |
| Type (Engine) | S 420 V8 (279 Hp) 4G-TRONIC |
| Start of production | March, 1994 |
| End of production | August, 1995 |
| 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) | 9.7-11.7 l/100 km (24.2 – 20.1 US mpg, 29.1 – 24.1 UK mpg, 10.3 – 8.5 km/l) |
| Fuel Type | Petrol (Gasoline) |
| Acceleration 0 – 100 km/h | 8.3 sec |
| Acceleration 0 – 62 mph | 8.3 sec |
| Acceleration 0 – 60 mph | 7.9 sec |
| Maximum speed | 245 km/h (152.24 mph) |
| Weight-to-power ratio | 7.1 kg/Hp, 140.2 Hp/tonne |
| Weight-to-torque ratio | 5 kg/Nm, 201 Nm/tonne |
| Power | 279 Hp @ 5700 rpm |
| Power per litre | 66.5 Hp/l |
| Torque | 400 Nm @ 3900 rpm (295.02 lb.-ft. @ 3900 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | M 119.971 |
| Engine displacement | 4196 cm3 (256.06 cu. in.) |
| Number of cylinders | 8 |
| Engine configuration | V-engine |
| Cylinder Bore | 92 mm (3.62 in.) |
| Piston Stroke | 78.9 mm (3.11 in.) |
| Compression ratio | 11:1 |
| Number of valves per cylinder | 4 |
| Fuel injection system | Multi-port manifold injection |
| Engine aspiration | Naturally aspirated engine |
| Valvetrain | DOHC |
| Engine oil capacity | 8 l (8.45 US qt | 7.04 UK qt) |
| Coolant | 16.5 l (17.44 US qt | 14.52 UK qt) |
| Kerb Weight | 1990 kg (4387.2 lbs.) |
| Max. weight | 2640 kg (5820.2 lbs.) |
| Max load | 650 kg (1433 lbs.) |
| Trunk (boot) space – minimum | 525 l (18.54 cu. ft.) |
| Fuel tank capacity | 100 l (26.42 US gal | 22 UK gal) |
| Length | 5113 mm (201.3 in.) |
| Width | 1886 mm (74.25 in.) |
| Height | 1486 mm (58.5 in.) |
| Wheelbase | 3040 mm (119.69 in.) |
| Front track | 1606 mm (63.23 in.) |
| Rear (Back) track | 1579 mm (62.17 in.) |
| Minimum turning circle | 12.18 m (39.96 ft.) |
| Drivetrain Architecture | Rear wheel drive |
| Drive wheel | Rear wheel drive |
| Number of gears and type of gearbox | 4 gears, automatic transmission G-TRONIC |
| Front suspension | Coil spring, Double wishbone, Transverse stabilizer |
| Rear suspension | Independent multi-link suspension, Transverse stabilizer, Coil spring |
| Front brakes | Ventilated discs |
| Rear brakes | Ventilated discs |
| Assisting systems | ABS (Anti-lock braking system) |
| Steering type | Cone worm with recirculation balls |
| Power steering | Hydraulic Steering |
| Tires size | 235/60 R16 |
| Wheel rims size | 7.5J x 16 |
Powertrain & Engine Architecture
The S 420 was powered by the M119.971 4.2-liter V8 engine. This engine, a cornerstone of Mercedes-Benz’s engineering prowess, featured a cast-iron block and aluminum cylinder heads. It utilized a multi-port fuel injection system, delivering precise fuel metering for optimal performance and efficiency. The engine’s dual overhead camshafts (DOHC) and four valves per cylinder contributed to its smooth power delivery and relatively high specific output for the era. The 4G-TRONIC automatic transmission, a four-speed unit, was specifically calibrated to complement the V8’s torque characteristics. This transmission, while not as sophisticated as later electronically controlled units, provided smooth and reliable shifting, prioritizing comfort over outright performance.
Driving Characteristics
The S 420 offered a driving experience focused on refinement and effortless cruising. The 279 horsepower and 295 lb-ft of torque provided ample power for highway passing and merging, but it wasn’t designed for aggressive acceleration. The 4G-TRONIC transmission, while smooth, had relatively widely spaced gear ratios, meaning the engine didn’t always feel as responsive as it could. Compared to the S320, the S 420 offered a noticeable performance increase. However, it lacked the outright sporting character of the higher-output S500. The suspension, tuned for comfort, absorbed bumps effectively, providing a plush ride. Steering was precise but lacked significant feedback.
Equipment & Trim Levels
The S 420 came standard with a comprehensive list of features expected of a luxury sedan in the mid-1990s. This included leather upholstery, power-adjustable front seats with memory function, automatic climate control, a premium sound system, and power windows and locks. Optional extras included a rear seat entertainment system, upgraded leather, a sunroof, and various wood trim options. The interior design emphasized understated elegance, with a focus on high-quality materials and meticulous craftsmanship. The dashboard layout was functional and intuitive, though it lacked the modern infotainment systems found in contemporary vehicles.
Chassis & Braking
The W140 S-Class featured a robust chassis designed for both comfort and safety. The S 420 utilized a coil spring, double wishbone suspension at the front and an independent multi-link suspension at the rear, both incorporating a transverse stabilizer bar. This setup provided excellent ride quality and handling stability. Braking duties were handled by ventilated discs on all four wheels, coupled with an Anti-lock Braking System (ABS) for enhanced stopping power and control. The steering system employed a cone worm with recirculation balls, offering precise steering feel.
Market Reception & Comparison
The S 420 was generally well-received by automotive critics. It was praised for its comfortable ride, refined interior, and powerful engine. However, some reviewers noted that the 4G-TRONIC transmission could feel sluggish at times, and the car’s size and weight made it less agile than some competitors. Compared to the S320, the S 420 offered a significant performance upgrade, justifying its higher price tag for buyers seeking more power. Against the S500, it represented a more sensible compromise between performance and cost. Fuel economy, while not a primary concern for S-Class buyers, was reasonable for a V8-powered luxury sedan of its size.
Legacy
The M119 engine, found in the S 420, is known for its durability and reliability when properly maintained. While the W140 S-Class as a whole can be expensive to maintain due to its complexity and age, the M119 engine itself is generally considered robust. Today, the S 420 is a sought-after classic car, appreciated by enthusiasts for its build quality, luxurious features, and timeless design. Well-maintained examples command respectable prices in the used car market, and the car remains a symbol of Mercedes-Benz’s commitment to engineering excellence.
