The Mercedes-Benz S 420 Long, produced from September 1995 to September 1998, represented a significant iteration of the W140 S-Class, specifically the facelifted model introduced in 1994. Positioned as a high-end luxury sedan, the S 420 Long offered a longer wheelbase than the standard W140, providing increased rear passenger legroom – a key feature for markets prioritizing chauffeur-driven transport. This variant occupied a middle ground within the W140 range, slotting between the entry-level S 320 and the flagship S 500 and S 600 models. It combined a powerful V8 engine with the convenience of a five-speed automatic transmission, aiming to deliver a refined and capable driving experience.
Technical Specifications
| Brand | Mercedes-Benz |
| Model | S-class |
| Generation | S-class Long (V140, facelift 1994) |
| Type (Engine) | S 420 V8 (279 Hp) 5G-TRONIC |
| Start of production | September, 1995 |
| End of production | September, 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 | 7.2 kg/Hp, 139.5 Hp/tonne |
| Weight-to-torque ratio | 5 kg/Nm, 200 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 | 2000 kg (4409.25 lbs.) |
| Max. weight | 2650 kg (5842.25 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 | 5213 mm (205.24 in.) |
| Width | 1886 mm (74.25 in.) |
| Height | 1486 mm (58.5 in.) |
| Wheelbase | 3140 mm (123.62 in.) |
| Front track | 1606 mm (63.23 in.) |
| Rear (Back) track | 1579 mm (62.17 in.) |
| Minimum turning circle | 12.51 m (41.04 ft.) |
| Drivetrain Architecture | 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 Long was powered by the M119.981 4.2-liter V8 engine. This engine, a cornerstone of Mercedes-Benz’s engineering prowess during the 1990s, featured a cast-iron block and aluminum cylinder heads. It employed multi-port fuel injection and a dual overhead camshaft (DOHC) valvetrain with four valves per cylinder, contributing to its smooth power delivery and relatively high specific output. The 11:1 compression ratio further enhanced performance. The engine was mated to Mercedes-Benz’s 5G-TRONIC five-speed automatic transmission, known for its smooth shifts and adaptability. This transmission featured electronic control, optimizing gear selection based on driving conditions and throttle input. The transmission was designed for comfort and refinement rather than outright performance, with gear ratios geared towards relaxed cruising.
Driving Characteristics
The S 420 Long offered a driving experience focused on comfort and effortless power. While not as overtly sporty as some of its competitors, the 279 horsepower and 400 Nm (295 lb-ft) of torque provided ample acceleration for highway merging and overtaking. The 0-60 mph time of around 7.9 seconds was respectable for a large luxury sedan of its era. The 5G-TRONIC transmission contributed to a smooth and refined driving experience, although it wasn’t particularly quick to downshift. Compared to the S 320, the S 420 offered a noticeable performance advantage, while remaining more accessible and less expensive than the higher-end S 500 and S 600 models. The longer wheelbase of the ‘Long’ variant did slightly diminish agility compared to the standard W140, but this was a trade-off accepted for the increased rear passenger space.
Equipment & Trim Levels
The S 420 Long came standard with a comprehensive array of luxury features, befitting its position in the Mercedes-Benz lineup. These included leather upholstery, power-adjustable front seats with memory function, automatic climate control, a premium sound system, and wood trim throughout the cabin. Optional extras were plentiful, including a rear entertainment system, massaging seats, a sunroof, and upgraded audio options. The interior design emphasized elegance and sophistication, with a focus on high-quality materials and meticulous craftsmanship. The S 420 Long typically featured a more restrained exterior appearance than the top-of-the-line models, lacking some of the chrome accents and unique styling elements found on the S 500 and S 600.
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, both incorporating a transverse stabilizer bar to reduce body roll. The S 420 Long was equipped with ventilated disc brakes on all four wheels, providing ample stopping power. Anti-lock braking system (ABS) was standard, enhancing safety and control during emergency braking situations. The steering system was a recirculating ball type with hydraulic power assistance, offering a balance of precision and ease of use. The suspension was tuned for a comfortable ride, prioritizing smoothness and isolation from road imperfections.
Market Reception & Comparison
The S 420 Long was generally well-received by automotive critics, who praised its luxurious interior, comfortable ride, and powerful engine. However, its fuel economy was often criticized as being poor, reflecting the inherent limitations of a large-displacement V8 engine. Compared to its competitors, such as the BMW 740iL and the Lexus LS 400, the S 420 Long offered a unique blend of German engineering, luxurious appointments, and a focus on rear passenger comfort. The S 420 Long’s reliability was generally good, although maintenance costs could be high due to the complexity of its systems and the cost of replacement parts.
Legacy
Today, the Mercedes-Benz S 420 Long (W140) is considered a classic luxury sedan, appreciated by enthusiasts for its build quality, engineering sophistication, and timeless design. The M119 V8 engine is known for its durability and relatively straightforward maintenance, although finding qualified mechanics familiar with these older Mercedes-Benz models can be a challenge. Well-maintained examples of the S 420 Long are becoming increasingly collectible, appealing to those seeking a luxurious and comfortable driving experience from a bygone era. The car represents a high point in Mercedes-Benz engineering, embodying the brand’s commitment to quality, innovation, and refinement.
