The Mercedes-Benz SL (R230) SL 350 V6 Automatic, produced from October 2002 to February 2006, represented a key entry point into the luxurious and iconic SL roadster range. Part of the R230 generation, which debuted in 2001, the SL 350 aimed to broaden the appeal of the SL by offering a more accessible price point and a focus on comfortable grand touring rather than outright performance. It occupied the lower-mid range of the lineup, positioned below the more powerful SL 500 and SL 600 models, and served as an alternative to the supercharged SL 320. The R230 SL series was built on the Mercedes-Benz M113 platform, known for its robust construction and advanced features.
Powertrain & Engine Architecture
The heart of the SL 350 is the M112 E 37 engine, a 3.7-liter naturally aspirated V6. This engine produced 245 horsepower at 5750 rpm and 350 Nm (258.15 lb-ft) of torque between 3000 and 4500 rpm. The engine features a 10:1 compression ratio, three valves per cylinder (SOHC valvetrain), and multi-port fuel injection. The V6 configuration provides a good balance of smoothness and power delivery. The engine’s longitudinal mounting within the chassis contributes to the car’s balanced handling characteristics.
Paired with the M112 E 37 engine is a 5-speed automatic transmission. This transmission, a staple of Mercedes-Benz vehicles during this period, was designed for smooth and refined shifts, prioritizing comfort over aggressive gear changes. While not offering the lightning-fast shifts of some contemporary transmissions, it was known for its reliability and suitability for long-distance cruising. The automatic transmission was a key factor in the SL 350’s appeal to buyers seeking a relaxed driving experience.
Engine Specifications
The M112 E 37 engine boasts a cylinder bore of 97 mm (3.82 in) and a piston stroke of 84 mm (3.31 in), resulting in a displacement of 3724 cm³ (227.25 cu. in). Engine oil capacity is 8 liters (8.45 US qt | 7.04 UK qt), and the coolant capacity is 10.8 liters (11.41 US qt | 9.5 UK qt). The engine is designed for use with specific oil formulations, and adherence to Mercedes-Benz’s recommended oil specifications is crucial for longevity.
Driving Characteristics
The SL 350 Automatic delivers a comfortable and refined driving experience. Acceleration from 0 to 100 km/h (0-62 mph) takes approximately 7.2 seconds, while 0-60 mph is achieved in around 6.8 seconds. Top speed is electronically limited to 250 km/h (155.34 mph). Compared to the higher-output SL 500 or SL 600, the SL 350 feels less urgent in its acceleration. However, the V6 provides ample power for everyday driving and effortless highway cruising. The automatic transmission’s gear ratios are tuned for smooth transitions and fuel efficiency, rather than maximizing performance. The car’s weight-to-power ratio of 6.9 kg/Hp and weight-to-torque ratio of 4.8 kg/Nm reflect its balanced, but not overtly sporty, character.
The SL 350’s driving experience is further enhanced by its rear-wheel drive configuration, which contributes to balanced handling. While not a dedicated sports car, the SL 350 offers a confident and predictable driving experience, making it suitable for both leisurely drives and longer journeys.
Equipment & Trim Levels
The SL 350 came standard with a comprehensive array of features befitting a luxury roadster. Standard equipment typically included leather upholstery, automatic climate control, power-adjustable seats, a premium sound system, and a retractable hardtop. The retractable hardtop was a defining feature of the R230 SL, offering the security and weather protection of a coupe with the open-air enjoyment of a convertible. Optional extras included features such as upgraded sound systems (often Bose or Harman Kardon), navigation systems, bi-xenon headlights, and various interior trim options. The interior dashboard configuration was typical of Mercedes-Benz during this era, featuring a blend of wood trim, metallic accents, and a user-friendly layout.
Chassis & Braking
The SL 350 utilizes an independent multi-link suspension system at both the front and rear, incorporating a transverse stabilizer bar to minimize body roll. This suspension setup provides a comfortable ride quality while maintaining good handling characteristics. The car is equipped with ventilated disc brakes on all four wheels, providing ample stopping power. An Anti-lock Braking System (ABS) is standard, enhancing safety and control during emergency braking situations. The steering system is a hydraulic power steering rack and pinion, offering precise and responsive steering feel. The SL 350 rides on 255/45 R 17 98 W tires mounted on 8.5 J x 17 H 2 wheel rims.
Market Reception & Comparison
The SL 350 was generally well-received by automotive critics as a more accessible entry point into the SL range. It was praised for its comfortable ride, refined interior, and the convenience of the retractable hardtop. However, some critics noted that its performance was not as exhilarating as the more powerful SL 500 or SL 600 models. Fuel economy, at 11.7 l/100 km combined (20.1 US mpg, 24.1 UK mpg), was typical for a luxury roadster of its size and engine displacement. CO2 emissions were rated at 276 g/km (Euro 4 standard). Compared to the SL 320 (supercharged), the SL 350 offered a slightly different driving character, with a more linear power delivery and a focus on refinement. The SL 350’s reliability was generally considered good, benefiting from Mercedes-Benz’s reputation for engineering quality.
Technical Specifications
| Brand | Mercedes-Benz |
| Model | SL |
| Generation | SL (R230) |
| Type (Engine) | SL 350 V6 (245 Hp) Automatic |
| Start of production | October, 2002 |
| End of production | February, 2006 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Roadster |
| Seats | 2 |
| Doors | 2 |
| Fuel consumption (economy) – urban (NEDC) | 17.5 l/100 km (13.4 US mpg, 16.1 UK mpg, 5.7 km/l) |
| Fuel consumption (economy) – extra urban (NEDC) | 8.3 l/100 km (28.3 US mpg, 34 UK mpg, 12 km/l) |
| Fuel consumption (economy) – combined (NEDC) | 11.7 l/100 km (20.1 US mpg, 24.1 UK mpg, 8.5 km/l) |
| CO2 emissions (NEDC) | 276 g/km |
| Fuel Type | Petrol (Gasoline) |
| Acceleration 0 – 100 km/h | 7.2 sec |
| Acceleration 0 – 62 mph | 7.2 sec |
| Acceleration 0 – 60 mph | 6.8 sec |
| Maximum speed | 250 km/h (155.34 mph) |
| Emission standard | Euro 4 |
| Weight-to-power ratio | 6.9 kg/Hp, 145.8 Hp/tonne |
| Weight-to-torque ratio | 4.8 kg/Nm, 208.3 Nm/tonne |
| Power | 245 Hp @ 5750 rpm |
| Torque | 350 Nm @ 3000-4500 rpm (258.15 lb.-ft. @ 3000-4500 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | M 112 E 37 |
| Engine displacement | 3724 cm3 (227.25 cu. in.) |
| Number of cylinders | 6 |
| Engine configuration | V-engine |
| Cylinder Bore | 97 mm (3.82 in.) |
| Piston Stroke | 84 mm (3.31 in.) |
| Compression ratio | 10:1 |
| Number of valves per cylinder | 3 |
| Fuel injection system | Multi-port manifold injection |
| Engine aspiration | Naturally aspirated engine |
| Valvetrain | SOHC |
| Engine oil capacity | 8 l (8.45 US qt | 7.04 UK qt) |
| Coolant | 10.8 l (11.41 US qt | 9.5 UK qt) |
| Kerb Weight | 1680 kg (3703.77 lbs.) |
| Max. weight | 2050 kg (4519.48 lbs.) |
| Max load | 370 kg (815.71 lbs.) |
| Trunk (boot) space – minimum | 235 l (8.3 cu. ft.) |
| Trunk (boot) space – maximum | 317 l (11.19 cu. ft.) |
| Fuel tank capacity | 80 l (21.13 US gal | 17.6 UK gal) |
| Length | 4535 mm (178.54 in.) |
| Width | 1827 mm (71.93 in.) |
| Height | 1317 mm (51.85 in.) |
| Wheelbase | 2560 mm (100.79 in.) |
| Drive wheel | Rear wheel drive |
| Number of gears and type of gearbox | 5 gears, automatic transmission |
Legacy
The SL 350 V6 Automatic, while not the most sought-after variant of the R230 SL, remains a desirable option in the used car market. Its combination of luxury, comfort, and relative affordability makes it an attractive choice for buyers seeking a classic Mercedes-Benz roadster experience. The M112 engine is known for its durability, and with proper maintenance, can provide many years of reliable service. However, like all vehicles of this age, potential buyers should be aware of potential issues such as wear and tear on suspension components, electrical system glitches, and the need for regular maintenance of the retractable hardtop mechanism. Overall, the SL 350 represents a well-rounded and enjoyable entry point into the world of Mercedes-Benz SL ownership.
