The Mercedes-Benz S 420, part of the W140 generation S-Class produced from September 1995 to August 1998, represented a compelling blend of luxury, performance, and advanced technology for its time. Positioned within the facelifted W140 range (introduced in 1994), the S 420 served as a mid-range offering, slotting between the six-cylinder S 320 and the flagship V12-powered S 600. It aimed to provide a more spirited driving experience than the S 320 while remaining more accessible than the ultra-luxury S 600. The W140 S-Class, known for its robust build quality and over-engineered design, established a new benchmark for automotive refinement and safety.
Technical Specifications
| Brand | Mercedes-Benz |
| Model | S-class |
| Generation | S-class (W140, facelift 1994) |
| Type (Engine) | S 420 V8 (279 Hp) 5G-TRONIC |
| Start of production | September, 1995 |
| End of production | August, 1998 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Sedan |
| Seats | 5 |
| Doors | 4 |
| Fuel consumption (economy) – urban (NEDC) | 21.4 l/100 km (11 US mpg, 13.2 UK mpg, 4.7 km/l) |
| Fuel consumption (economy) – extra urban (NEDC) | 11.2 l/100 km (21 US mpg, 25.2 UK mpg, 8.9 km/l) |
| Fuel consumption (economy) – combined (NEDC) | 14.9 l/100 km (15.8 US mpg, 19 UK mpg, 6.7 km/l) |
| CO2 emissions (NEDC) | 355 g/km |
| 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 119.981 |
| 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 | 7.5 l (7.93 US qt | 6.6 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 | 5 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 M119.981 4.2-liter V8 engine. This engine, a naturally aspirated powerplant, featured a cast-iron block and aluminum cylinder heads. It utilized a Bosch Motronic engine management system and multi-port fuel injection. The dual overhead camshafts (DOHC) operated four valves per cylinder, contributing to its respectable power output. The 5G-TRONIC automatic transmission, a five-speed unit, was standard. This transmission was known for its smooth shifts and adaptability, though it lacked the sportiness of some contemporary manual transmissions. The engine’s design prioritized refinement and durability over outright performance, a characteristic typical of Mercedes-Benz engineering at the time.
Driving Characteristics
The S 420 offered a comfortable and composed driving experience. While not overtly sporty, the 279 horsepower and 295 lb-ft of torque provided ample power for effortless cruising and confident overtaking. The 5G-TRONIC transmission, while smooth, could feel somewhat hesitant during quick downshifts. Compared to the S 320, the S 420 offered noticeably stronger acceleration. However, it lacked the raw power and responsiveness of the S 600. 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 luxury features, including leather upholstery, power-adjustable front seats with memory function, automatic climate control, a premium sound system, and wood trim. Optional extras included rear seats with massage function, a sunroof, and upgraded audio systems. The interior design emphasized elegance and sophistication, with high-quality materials and meticulous attention to detail. The S 420 typically featured burl walnut trim, though other wood options were available.
Chassis & Braking
The W140 S-Class featured a robust chassis with independent suspension all around. The front suspension utilized coil springs and double wishbones, while the rear employed a multi-link setup. This configuration provided a comfortable ride and good handling characteristics. The S 420 was equipped with ventilated disc brakes on all four wheels, along with ABS (Anti-lock Braking System) as standard. The braking system provided ample stopping power, though it lacked the advanced features found on some later models.
Market Reception & Comparison
The S 420 was generally well-received by automotive critics. It was praised for its comfortable ride, luxurious interior, and refined powertrain. However, some critics noted its relatively high fuel consumption and the somewhat dated feel of the 5G-TRONIC transmission. Compared to the S 320, the S 420 offered a significant performance upgrade, justifying its higher price tag for buyers seeking more power. Against the S 600, it represented a more sensible option for those who didn’t require the ultimate in luxury and performance.
Legacy
The M119 engine, found in the S 420, is known for its durability and reliability. With proper maintenance, these engines can accumulate high mileage without major issues. The W140 S-Class, as a whole, has gained a reputation as a well-built and over-engineered vehicle. Today, the S 420 is a sought-after classic among Mercedes-Benz enthusiasts, appreciated for its blend of luxury, performance, and timeless design. While fuel economy is a concern by modern standards, the S 420 remains a compelling choice for those seeking a comfortable and refined grand tourer.
