The Mercedes-Benz 560 SEC, part of the C126 series facelift produced from June 1985 to September 1987, represented the pinnacle of luxury coupe design for its time. Positioned as the top-of-the-line variant within the C126 coupe range, it offered a significant step up in performance and refinement compared to the 380 SEC and 420 SEC models. The 560 SEC catered to buyers seeking a grand touring experience with a powerful V8 engine and a sophisticated automatic transmission. It was a flagship model, embodying Mercedes-Benz’s commitment to engineering excellence and opulent comfort. The C126 platform itself was a significant departure from its predecessor, offering increased interior space and improved handling characteristics.
Technical Specifications
| Brand | Mercedes-Benz |
| Model | S-class |
| Generation | S-class Coupe (C126, facelift 1985) |
| Type (Engine) | 560 SEC V8 CAT (242 Hp) Automatic |
| Start of production | June, 1985 |
| End of production | September, 1987 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Coupe |
| Seats | 4 |
| Doors | 2 |
| Fuel consumption (urban) | 18 l/100 km (13.1 US mpg, 15.7 UK mpg, 5.6 km/l) |
| Fuel consumption (extra urban) | 11.4 l/100 km (20.6 US mpg, 24.8 UK mpg, 8.8 km/l) |
| Fuel Type | Petrol (Gasoline) |
| Acceleration 0 – 100 km/h | 7.6 sec |
| Acceleration 0 – 62 mph | 7.6 sec |
| Acceleration 0 – 60 mph | 7.2 sec |
| Maximum speed | 228 km/h (141.67 mph) |
| Weight-to-power ratio | 7.2 kg/Hp, 138.3 Hp/tonne |
| Weight-to-torque ratio | 4.5 kg/Nm, 222.9 Nm/tonne |
| Power | 242 Hp @ 4800 rpm |
| Power per litre | 43.6 Hp/l |
| Torque | 390 Nm @ 3500 rpm (287.65 lb.-ft. @ 3500 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | M 117 E 56 / 117.968 |
| Engine displacement | 5547 cm3 (338.5 cu. in.) |
| Number of cylinders | 8 |
| Engine configuration | V-engine |
| Cylinder Bore | 96.5 mm (3.8 in.) |
| Piston Stroke | 94.8 mm (3.73 in.) |
| Compression ratio | 9:1 |
| Number of valves per cylinder | 2 |
| 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 | 13.5 l (14.27 US qt | 11.88 UK qt) |
| Kerb Weight | 1750 kg (3858.09 lbs.) |
| Max. weight | 2210 kg (4872.22 lbs.) |
| Max load | 460 kg (1014.13 lbs.) |
| Fuel tank capacity | 90 l (23.78 US gal | 19.8 UK gal) |
| Length | 4935 mm (194.29 in.) |
| Width | 1828 mm (71.97 in.) |
| Height | 1402 mm (55.2 in.) |
| Wheelbase | 2845 mm (112.01 in.) |
| Front track | 1555 mm (61.22 in.) |
| Rear track | 1527 mm (60.12 in.) |
| Drivetrain Architecture | The Internal combustion engine (ICE) drives the rear wheels of the vehicle. |
| Drive wheel | Rear wheel drive |
| Number of gears and type of gearbox | 4 gears, automatic transmission |
| Front suspension | Double wishbone |
| Rear suspension | Threaded twist beam |
| Front brakes | Ventilated discs |
| Rear brakes | Disc |
| Assisting systems | ABS (Anti-lock braking system) |
| Steering type | Cone worm with recirculation balls |
| Power steering | Hydraulic Steering |
| Tires size | Front wheel tires: 215/65 R15Rear wheel tires: 215/65 R15 |
| Wheel rims size | Front wheel rims: 7J x 15Rear wheel rims: 7J x 15 |
Powertrain & Engine Architecture
The heart of the 560 SEC was the M117 E 56 engine, a 5.5-liter (5547 cc) naturally aspirated V8. This engine, a cornerstone of Mercedes-Benz’s engineering prowess, featured a cast-iron block and aluminum cylinder heads. It utilized a single overhead camshaft (SOHC) design with two valves per cylinder. The engine employed Bosch K-Jetronic fuel injection, a mechanical system known for its reliability and precise fuel delivery. The catalytic converter (“CAT” in the model designation) was standard, reflecting increasing emissions regulations. The engine produced 242 horsepower at 4800 rpm and 390 Nm (287.65 lb-ft) of torque at 3500 rpm. Paired with a four-speed automatic transmission (typically the 722.3 series), the powertrain delivered smooth and refined shifts. The transmission was designed to prioritize comfort and ease of driving, rather than outright performance.
Driving Characteristics
The 560 SEC offered a distinctly grand touring experience. While not a sports car, the combination of the powerful V8 and the automatic transmission provided brisk acceleration – 0 to 60 mph in approximately 7.2 seconds. The automatic transmission, while smooth, did result in some power loss compared to the manual transmission options available in other C126 models. The gear ratios were optimized for comfortable cruising at highway speeds, with a focus on relaxed power delivery. The suspension, tuned for comfort, absorbed bumps effectively, providing a smooth ride. However, the car’s weight (approximately 3858 lbs) was noticeable in cornering, resulting in some body roll. Overall, the driving experience was characterized by refinement, quietness, and a sense of effortless power.
Equipment & Trim Levels
The 560 SEC came standard with a comprehensive list of luxury features. Leather upholstery was standard, along with power-adjustable front seats with memory function. Climate control, power windows, power door locks, and a sunroof were also included as standard equipment. The interior trim was typically finished in wood veneer, adding to the car’s opulent ambiance. Optional extras included a premium sound system, heated seats, and a rear seat entertainment system. The exterior featured chrome trim, alloy wheels, and a distinctive coupe silhouette. The level of standard equipment reflected the 560 SEC’s position as the flagship coupe model.
Chassis & Braking
The C126 coupe chassis featured independent suspension all around. The front suspension utilized a double wishbone design, while the rear employed a threaded twist beam. This setup provided a good balance between ride comfort and handling. Braking duties were handled by ventilated disc brakes at the front and solid disc brakes at the rear. An Anti-lock Braking System (ABS) was standard, enhancing safety and control during hard braking. The steering was a recirculating ball system with hydraulic power assistance, providing a comfortable and manageable driving experience. The tires were typically 215/65 R15, offering a good compromise between grip and ride comfort.
Market Reception & Comparison
The 560 SEC was generally well-received by automotive critics. It was praised for its luxurious interior, powerful engine, and comfortable ride. However, some critics noted the car’s weight and its relatively high price. Compared to the 380 SEC and 420 SEC, the 560 SEC offered significantly more performance and a more prestigious image. Fuel economy, however, was considerably lower. The 560 SEC competed with other high-end grand touring coupes, such as the BMW 6 Series and the Jaguar XJS. Its reputation for reliability, while generally good, was somewhat affected by the complexity of the K-Jetronic fuel injection system, which could require specialized maintenance.
Legacy
The Mercedes-Benz 560 SEC remains a highly sought-after classic car today. Its combination of luxury, performance, and timeless design has made it a favorite among collectors and enthusiasts. The M117 engine, while aging, is known for its durability when properly maintained. However, finding qualified mechanics familiar with the K-Jetronic fuel injection system can be challenging. Parts availability is generally good, but some components can be expensive. Well-maintained examples of the 560 SEC command premium prices in the used car market, reflecting their enduring appeal and status as a symbol of 1980s automotive luxury.
