The Mercedes-Benz S 320 (W140) represented a significant step forward in luxury and technology when it was introduced in 1993 and remained in production through 1994. Positioned as a mid-range offering within the expansive W140 S-Class lineup, it slotted between the entry-level S 280 and the flagship S 420 and S 500 models. The S 320 aimed to provide a compelling blend of performance, refinement, and advanced features, appealing to buyers who desired the S-Class experience without the higher price tag of the top-tier variants. It was a key model for Mercedes-Benz in establishing its dominance in the full-size luxury sedan segment, particularly in markets like Europe and North America.
Technical Specifications
| Brand | Mercedes-Benz |
| Model | S-class |
| Generation | S-class (W140) |
| Type (Engine) | S 320 (231 Hp) 4 Automatic |
| Start of production | 1993 |
| End of production | 1994 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Sedan |
| Seats | 5 |
| Doors | 4 |
| Fuel consumption (economy) – urban | 14.5 l/100 km (16.2 US mpg, 19.5 UK mpg, 6.9 km/l) |
| Fuel consumption (economy) – extra urban | 9.6 l/100 km (24.5 US mpg, 29.4 UK mpg, 10.4 km/l) |
| Fuel consumption (economy) – combined | 11.9 l/100 km (19.8 US mpg, 23.7 UK mpg, 8.4 km/l) |
| Fuel Type | Petrol (Gasoline) |
| Acceleration 0 – 100 km/h | 8.9 sec |
| Acceleration 0 – 62 mph | 8.9 sec |
| Acceleration 0 – 60 mph | 8.5 sec |
| Maximum speed | 225 km/h (139.81 mph) |
| Weight-to-power ratio | 8.2 kg/Hp, 122.2 Hp/tonne |
| Weight-to-torque ratio | 6 kg/Nm, 166.7 Nm/tonne |
| Power | 231 Hp @ 5600 rpm |
| Power per litre | 72.2 Hp/l |
| Torque | 315 Nm @ 3750 rpm (232.33 lb.-ft. @ 3750 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | M 104 E 32 |
| Engine displacement | 3199 cm3 (195.21 cu. in.) |
| Number of cylinders | 6 |
| Engine configuration | Inline |
| Cylinder Bore | 89.9 mm (3.54 in.) |
| Piston Stroke | 84 mm (3.31 in.) |
| Compression ratio | 10:1 |
| 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 | 14.5 l (15.32 US qt | 12.76 UK qt) |
| Kerb Weight | 1890 kg (4166.74 lbs.) |
| Max. weight | 2550 kg (5621.79 lbs.) |
| Max load | 660 kg (1455.05 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 | 1485 mm (58.46 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 | 11.7 m (38.39 ft.) |
| Drivetrain Architecture | Rear wheel drive |
| Drive wheel | Rear wheel drive |
| Number of gears and type of gearbox | 4 gears, automatic transmission |
| Front suspension | Double wishbone |
| Rear suspension | Independent multi-link spring suspension with stabilizer |
| Front brakes | Ventilated discs |
| Rear brakes | Disc |
| Assisting systems | ABS (Anti-lock braking system), Hydraulic Steering |
| Tires size | 235/60 R16 |
| Wheel rims size | 16 |
Powertrain & Engine Architecture
The heart of the S 320 was the M104 E 32 engine, a 3.2-liter inline-six cylinder powerplant. This engine was a significant departure from the V8 engines traditionally found in the S-Class, representing a move towards more efficient and technologically advanced designs. The M104 featured a cast iron block with an aluminum cylinder head, incorporating a double overhead camshaft (DOHC) valvetrain with four valves per cylinder. Fuel delivery was handled by a Bosch Motronic multi-port fuel injection system, optimizing combustion for both power and economy. The engine produced 231 horsepower at 5600 rpm and 315 Nm (232 lb-ft) of torque at 3750 rpm. Paired with the engine was a four-speed automatic transmission, providing smooth and refined gear changes. This transmission was specifically tuned to complement the engine’s characteristics, prioritizing comfort and drivability over outright performance.
Driving Characteristics
The S 320, with its 3.2-liter engine and automatic transmission, offered a distinctly different driving experience compared to its S 420 or S 500 siblings. While not as overtly powerful, the S 320 provided ample power for comfortable cruising and effortless acceleration. The automatic transmission, while smooth, did result in a slight reduction in responsiveness compared to the available manual transmission options in other S-Class models. The gear ratios were optimized for fuel efficiency and relaxed highway driving. The 0-60 mph time of around 8.5 seconds was respectable for the era, but noticeably slower than the V8-powered variants. However, the S 320 excelled in providing a refined and comfortable ride, thanks to its sophisticated suspension system and well-insulated cabin.
Equipment & Trim Levels
The S 320 came standard with a comprehensive array of luxury features, befitting its status as a flagship sedan. Standard equipment included leather upholstery, power-adjustable front seats with memory function, automatic climate control, a premium sound system, and power windows and locks. The interior trim was typically finished in wood veneer, adding to the sense of opulence. Optional extras included a sunroof, upgraded sound systems, rear seat entertainment, and various driver-assistance features. The S 320’s trim level was generally considered mid-range, offering a balance of luxury and features without the extensive customization options available on the higher-end models.
Chassis & Braking
The W140 S-Class featured a robust chassis with double wishbone suspension at the front and an independent multi-link spring suspension with a stabilizer bar at the rear. This suspension setup provided a smooth and controlled ride, even on uneven surfaces. The S 320 was equipped with ventilated disc brakes at the front and solid disc brakes at the rear, providing adequate stopping power for its weight and performance. Anti-lock braking system (ABS) was standard, enhancing safety and stability during emergency braking maneuvers. The steering was hydraulic power-assisted, offering precise and effortless control.
Market Reception & Comparison
The S 320 was generally well-received by automotive critics, who praised its refined ride, comfortable interior, and advanced features. However, some reviewers noted that its performance was not as exhilarating as the V8-powered models. Fuel economy was considered reasonable for a vehicle of its size and class, averaging around 19.8 US mpg in combined driving. Compared to the S 420 and S 500, the S 320 offered a more affordable entry point into the S-Class range, making it an attractive option for buyers who prioritized value and efficiency. Reliability was generally good, although the complex electronic systems of the W140 generation could be prone to occasional issues.
Legacy
The W140 S 320 has become a sought-after classic among Mercedes-Benz enthusiasts. The M104 engine is known for its durability and relatively straightforward maintenance. Well-maintained examples are still capable of providing years of reliable service. The S 320 represents a high point in Mercedes-Benz engineering, combining luxury, technology, and refinement in a package that remains appealing today. In the used car market, the S 320 typically commands a premium over other W140 variants due to its balance of performance, economy, and reliability. It stands as a testament to Mercedes-Benz’s commitment to building high-quality, long-lasting automobiles.
