The Mercedes-Benz GLC 450d 4MATIC Coupe (C254) represents a compelling blend of performance, luxury, and efficiency within the GLC Coupe range. Introduced in October 2023, this variant occupies a premium position in the lineup, offering a significant step up in power and torque compared to lower-tier models like the GLC 200d or 300d. It’s positioned as a sophisticated choice for buyers seeking a sporty SUV coupe experience with the added benefit of mild hybrid technology. The C254 generation GLC Coupe builds upon the success of the preceding C238 model, incorporating updated styling, enhanced technology, and improved driving dynamics.
Technical Specifications
| Brand | Mercedes-Benz |
| Model | GLC |
| Generation | GLC Coupe (C254) |
| Type | GLC 450d (367 Hp) Mild Hybrid 4MATIC 9G-TRONIC |
| Start of production | October, 2023 |
| Powertrain Architecture | MHEV (Mild Hybrid Electric Vehicle) |
| Body type | Coupe, SUV |
| Seats | 5 |
| Doors | 5 |
| Combined fuel consumption (WLTP) | 6.3-6.9 l/100 km (37.3 – 34.1 US mpg, 44.8 – 40.9 UK mpg, 15.9 – 14.5 km/l) |
| CO2 emissions (WLTP) | 166-181 g/km |
| Fuel Type | Diesel |
| Acceleration 0 – 100 km/h | 4.7 sec |
| Acceleration 0 – 62 mph | 4.7 sec |
| Acceleration 0 – 60 mph | 4.5 sec |
| Maximum speed | 250 km/h (155.34 mph) |
| Emission standard | Euro 6e |
| Weight-to-power ratio | 5.5 kg/Hp, 181.2 Hp/tonne |
| Weight-to-torque ratio | 2.7 kg/Nm, 370.4 Nm/tonne |
| Battery voltage | 48 V |
| Battery technology | Lithium-ion (Li-Ion) |
| Electric motor power | 23 Hp |
| Electric motor Torque | 205 Nm (151.2 lb.-ft.) |
| Electric motor location | Between the combustion engine and the transmission |
| Power | 367 Hp @ 4000 rpm |
| Torque | 750 Nm @ 1350-2800 rpm (553.17 lb.-ft. @ 1350-2800 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | OM 656.830 |
| Engine displacement | 2989 cm3 (182.4 cu. in.) |
| Number of cylinders | 6 |
| Engine configuration | Inline |
| Compression ratio | 15.5:1 |
| Number of valves per cylinder | 4 |
| Fuel injection system | Diesel Commonrail |
| Engine aspiration | BiTurbo, Intercooler |
| Valvetrain | DOHC |
| Engine oil capacity | 8.5 l (8.98 US qt | 7.48 UK qt) |
| Kerb Weight | 2025 kg (4464.36 lbs.) |
| Max. weight | 2620 kg (5776.11 lbs.) |
| Max load | 595 kg (1311.75 lbs.) |
| Trunk (boot) space – minimum | 545 l (19.25 cu. ft.) |
| Trunk (boot) space – maximum | 1490 l (52.62 cu. ft.) |
| Fuel tank capacity | 62 l (16.38 US gal | 13.64 UK gal) |
| AdBlue tank | 24 l (6.34 US gal | 5.28 UK gal) |
| Max. roof load | 75 kg (165.35 lbs.) |
| Permitted trailer load with brakes (12%) | 2500 kg (5511.56 lbs.) |
| Permitted trailer load without brakes | 750 kg (1653.47 lbs.) |
| Permitted towbar download | 100 kg (220.46 lbs.) |
| Length | 4764 mm (187.56 in.) |
| Width | 1890 mm (74.41 in.) |
| Width including mirrors | 2076 mm (81.73 in.) |
| Height | 1605 mm (63.19 in.) |
| Wheelbase | 2888 mm (113.7 in.) |
| Front track | 1627 mm (64.06 in.) |
| Rear (Back) track | 1640 mm (64.57 in.) |
| Front overhang | 843 mm (33.19 in.) |
| Rear overhang | 1033 mm (40.67 in.) |
| Ride height (ground clearance) | 171-193 mm (6.73 – 7.6 in.) |
| Minimum turning circle (turning diameter) | 10.9 m (35.76 ft.) |
| Drivetrain Architecture | ICE and electric motor drive all four wheels, operating in mixed mode. |
| Drive wheel | All wheel drive (4×4) |
| Number of gears and type of gearbox | 9 gears, automatic transmission G-TRONIC |
| Front suspension | Independent multi-link suspension, Air Suspension – Optional |
| Rear suspension | Independent multi-link suspension, Air Suspension – Optional |
| Front brakes | Ventilated discs |
| Rear brakes | Ventilated discs |
Powertrain & Engine Architecture
At the heart of the GLC 450d lies the OM 656.830, a 3.0-liter inline-six cylinder diesel engine. This engine is a modern marvel of diesel technology, featuring a sophisticated bi-turbocharger system with variable geometry turbines (VGT) and an intercooler. This configuration delivers a substantial 367 horsepower at 4000 rpm and an impressive 750 Nm (553.17 lb-ft) of torque between 1350 and 2800 rpm. The engine utilizes a diesel commonrail direct injection system, ensuring precise fuel delivery and optimized combustion. The compression ratio is set at 15.5:1. The engine is paired with a 48-volt mild hybrid system, incorporating a 23 hp electric motor integrated between the engine and the 9G-TRONIC automatic transmission. This system provides a boost during acceleration, enables smoother start/stop functionality, and contributes to improved fuel efficiency. The 9G-TRONIC transmission itself is a nine-speed automatic, known for its smooth shifts and wide gear ratio spread, optimizing both performance and economy.
Driving Characteristics
The GLC 450d 4MATIC Coupe delivers a refined and powerful driving experience. The combination of the potent diesel engine and the 9G-TRONIC transmission results in brisk acceleration – 0 to 60 mph in approximately 4.5 seconds. The mild hybrid system provides an almost imperceptible boost during initial acceleration, enhancing responsiveness. The 9G-TRONIC transmission is well-tuned, offering seamless gear changes and keeping the engine within its optimal power band. Compared to the lower-powered GLC 200d or 300d variants, the 450d offers significantly more pulling power, making it more confident for overtaking and towing. While not as overtly sporty as some performance-focused SUVs, the GLC 450d strikes a good balance between comfort and performance.
Equipment & Trim Levels
The GLC 450d 4MATIC Coupe comes standard with a high level of equipment. This typically includes Mercedes-Benz’s MBUX infotainment system with a large touchscreen display, premium upholstery (often leather), heated front seats, a panoramic sunroof, and a comprehensive suite of driver-assistance systems such as adaptive cruise control, lane-keeping assist, and automatic emergency braking. Optional extras can include air suspension, upgraded audio systems (Burmester), and various interior trim packages. The interior design emphasizes luxury and technology, with high-quality materials and a modern aesthetic.
Chassis & Braking
The GLC 450d features a sophisticated chassis designed to provide a comfortable yet controlled ride. It utilizes an independent multi-link suspension at both the front and rear. Air suspension is available as an option, further enhancing ride quality and allowing for adjustable ride height. The braking system consists of ventilated discs on all four wheels, providing ample stopping power. Standard safety features include ABS (Anti-lock Braking System) and electronic stability control. Available options like 4-wheel steering enhance agility and maneuverability, particularly at lower speeds.
Market Reception & Comparison
The GLC 450d 4MATIC Coupe has been generally well-received by automotive critics. It’s praised for its powerful engine, refined ride, and luxurious interior. Fuel economy is respectable for a vehicle of its size and performance, with combined WLTP figures ranging from 6.3 to 6.9 l/100 km. Compared to the GLC 300d, the 450d offers a substantial performance upgrade, but at a higher price point. The 450d also provides a more compelling alternative to petrol-powered rivals, offering superior torque and fuel efficiency.
Legacy
The OM 656 engine family, including the OM 656.830 found in the GLC 450d, has proven to be a robust and reliable powerplant. Early indications suggest that the mild hybrid system adds to the engine’s longevity. As a relatively new model (2023 onwards), long-term reliability data is still emerging. However, given Mercedes-Benz’s reputation for build quality and the proven track record of the OM 656 engine, the GLC 450d 4MATIC Coupe is expected to hold its value well in the used car market and provide years of dependable service.
