The Mercedes-Benz S 320 (W140) represents a pivotal point in the S-Class lineage, produced between 1993 and 1994. Positioned as a mid-range offering within the W140 generation – which spanned from 1991 to 1998 – the S 320 aimed to balance luxury, performance, and relative affordability within the flagship model range. It served as a more accessible entry point to the W140 experience compared to the range-topping S 600 V12, while offering a step up in refinement and power over the S 280 and S 300 models. The W140 S-Class, as a whole, was a technological showcase for Mercedes-Benz, introducing innovations in safety, comfort, and engineering that would become hallmarks of the brand.
Technical Specifications
| Brand | Mercedes-Benz |
| Model | S-class |
| Generation | S-class (W140) |
| Type (Engine) | S 320 (231 Hp) 5 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 | 14.9 l/100 km (15.8 US mpg, 19 UK mpg, 6.7 km/l) |
| Fuel consumption (economy) – extra urban | 8.8 l/100 km (26.7 US mpg, 32.1 UK mpg, 11.4 km/l) |
| Fuel consumption (economy) – combined | 11.5 l/100 km (20.5 US mpg, 24.6 UK mpg, 8.7 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 | 5 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 S 320 was powered by 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 top-tier Mercedes-Benz models, representing a move towards more efficient and technologically advanced designs. The M104 featured a four-valve per cylinder DOHC (Double Overhead Camshaft) valvetrain, and a Bosch Motronic fuel injection system. This system precisely controlled fuel delivery for optimal combustion and emissions. The engine’s robust construction and sophisticated engineering contributed to its reputation for reliability. The five-speed automatic transmission (typically the 5G-Tronic) was specifically tuned to complement the engine’s characteristics, providing smooth and refined gear changes. This transmission was known for its adaptability, offering both comfort and performance-oriented shift programs.
Driving Characteristics
The S 320, with its 231 horsepower and 232 lb-ft of torque, offered a comfortable and composed driving experience. While not overtly sporty, it provided ample power for effortless cruising and confident overtaking. Acceleration from 0-60 mph took around 8.5 seconds, respectable for a large luxury sedan of the era. The automatic transmission, while smooth, did contribute to a slight reduction in responsiveness compared to the available manual transmission options in other S-Class variants. The gear ratios were optimized for fuel efficiency and relaxed highway driving, rather than aggressive acceleration. The inline-six engine delivered a smooth and refined power delivery, lacking the low-end grunt of a V8 but offering a pleasingly linear response throughout the rev range.
Equipment & Trim Levels
The S 320 came standard with a comprehensive array of luxury features, befitting its status as a flagship sedan. These included leather upholstery, power-adjustable front seats with memory function, automatic climate control, a premium sound system, and power windows and locks. Optional extras were plentiful, allowing buyers to customize their S 320 to their specific preferences. Popular options included a sunroof, upgraded sound systems, rear seat entertainment, and various wood trim options. The interior design emphasized understated elegance and high-quality materials, creating a comfortable and refined cabin environment.
Chassis & Braking
The W140 S-Class featured a sophisticated chassis design, incorporating a double wishbone front suspension and an independent multi-link rear suspension with a stabilizer bar. This setup provided a comfortable ride while maintaining good handling characteristics. The S 320 was equipped with ventilated disc brakes at the front and solid disc brakes at the rear, providing ample stopping power. Anti-lock braking system (ABS) was standard, enhancing safety and control during emergency braking situations. The steering was hydraulically assisted, offering a precise and responsive feel.
Market Reception & Comparison
The S 320 was generally well-received by automotive critics, who praised its blend of luxury, performance, and refinement. It was seen as a more sensible alternative to the more expensive and powerful S 600 V12, offering a similar level of comfort and features at a lower price point. Compared to the S 280 and S 300, the S 320 offered a noticeable performance upgrade, making it a more appealing choice for drivers who valued a more engaging driving experience. Fuel economy was reasonable for a vehicle of its size and class, although it was still relatively high by modern standards. Reliability was generally good, although the W140 S-Class, with its complex electronics, could be prone to certain issues as it aged.
Legacy
The M104 engine, found in the S 320, is regarded as a robust and reliable powerplant. Well-maintained examples continue to provide years of service. Today, the W140 S 320 is gaining recognition as a classic Mercedes-Benz, appreciated for its build quality, luxurious features, and timeless design. The car’s relative affordability compared to other W140 variants makes it an attractive option for enthusiasts looking to experience the iconic S-Class of the early 1990s. Parts availability is generally good, although some specialized components may be difficult to source. The S 320 represents a high point in Mercedes-Benz engineering and design, and its legacy continues to endure.
