The Mercedes-Benz GLC 300d Coupe (C254), launched in July 2023, represents a blend of luxury, performance, and efficiency within the compact SUV segment. Positioned as a mid-range offering in the GLC Coupe lineup, it slots between the base GLC 200 and the higher-performance AMG variants. This model distinguishes itself through its diesel powertrain, mild-hybrid technology, and standard 4MATIC all-wheel drive, appealing to buyers seeking a refined driving experience with enhanced fuel economy. The C254 generation builds upon the success of the preceding C238 model, incorporating updated styling, technology, and a more sophisticated interior.
Technical Specifications
| Brand | Mercedes-Benz |
| Model | GLC |
| Generation | GLC Coupe (C254) |
| Type | GLC 300d (269 Hp) Mild Hybrid 4MATIC 9G-TRONIC |
| Start of production | July, 2023 |
| Powertrain Architecture | MHEV (Mild Hybrid Electric Vehicle) |
| Body type | Coupe, SUV |
| Seats | 5 |
| Doors | 5 |
| Combined fuel consumption (WLTP) | 5.5-6.1 l/100 km (42.8 – 38.6 US mpg, 51.4 – 46.3 UK mpg, 18.2 – 16.4 km/l) |
| CO2 emissions (WLTP) | 145-160 g/km |
| Fuel Type | Diesel |
| Acceleration 0 – 100 km/h | 6.4 sec |
| Acceleration 0 – 62 mph | 6.4 sec |
| Acceleration 0 – 60 mph | 6.1 sec |
| Maximum speed | 249 km/h (154.72 mph) |
| Emission standard | Euro 6d-ISC-FCM |
| Weight-to-power ratio | 7.6 kg/Hp, 131.5 Hp/tonne |
| Weight-to-torque ratio | 3.7 kg/Nm, 268.9 Nm/tonne |
| Battery voltage | 48 V |
| Battery technology | Lithium-ion (Li-Ion) |
| Electric motor power | 23 Hp |
| Electric motor Torque | 200 Nm (147.51 lb.-ft.) |
| Electric motor location | Between the combustion engine and the transmission |
| Power | 269 Hp @ 4200 rpm |
| Torque | 550 Nm @ 1800-2200 rpm (405.66 lb.-ft. @ 1800-2200 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | OM 654 M |
| Engine displacement | 1993 cm3 (121.62 cu. in.) |
| Number of cylinders | 4 |
| Engine configuration | Inline |
| Number of valves per cylinder | 4 |
| Fuel injection system | Diesel Commonrail |
| Engine aspiration | Twin-Turbo, Intercooler |
| Valvetrain | DOHC |
| Kerb Weight | 2045 kg (4508.45 lbs.) |
| Max. weight | 2570 kg (5665.88 lbs.) |
| Max load | 525 kg (1157.43 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) |
| Permitted trailer load with brakes (12%) | 2500 kg (5511.56 lbs.) |
| Permitted towbar download | 100 kg (220.46 lbs.) |
| Length | 4769 mm (187.76 in.) |
| Width | 1920 mm (75.59 in.) |
| Width including mirrors | 2076 mm (81.73 in.) |
| Height | 1606 mm (63.23 in.) |
| Wheelbase | 2888 mm (113.7 in.) |
| Front track | 1628 mm (64.09 in.) |
| Rear (Back) track | 1642 mm (64.65 in.) |
| Front overhang | 848 mm (33.39 in.) |
| Rear overhang | 1033 mm (40.67 in.) |
| Ride height (ground clearance) | 158 mm (6.22 in.) |
| Minimum turning circle (turning diameter) | 10.9 m (35.76 ft.) |
| Front brakes | Ventilated discs |
| Rear brakes | Ventilated discs |
| Drive wheel | All wheel drive (4×4) |
| Number of gears and type of gearbox | 9 gears, automatic transmission G-TRONIC |
| Front wheel tires | 235/55 R19 |
| Rear wheel tires | 255/50 R19 |
| Front wheel rims | 8J x 19 |
| Rear wheel rims | 9J x 19 |
Powertrain & Engine Architecture
The heart of the GLC 300d Coupe is the OM 654 M 2.0-liter inline-four cylinder diesel engine. This engine is a cornerstone of Mercedes-Benz’s modern diesel offerings, known for its efficiency and refinement. It utilizes a twin-turbocharger setup with variable geometry turbines (VGT) and an intercooler to deliver a robust 269 horsepower at 4200 rpm and a substantial 550 Nm (405.66 lb.-ft.) of torque between 1800 and 2200 rpm. The engine employs a sophisticated diesel commonrail direct injection system, ensuring precise fuel delivery and optimized combustion. The valvetrain features a double overhead camshaft (DOHC) design with four valves per cylinder. Crucially, this engine is paired with a 48-volt mild-hybrid system. This system incorporates a 23 hp electric motor integrated between the engine and the 9G-TRONIC automatic transmission, providing a boost during acceleration and enabling features like coasting with the engine shut off to improve fuel economy. The 9G-TRONIC transmission itself is a nine-speed automatic, known for its smooth shifts and wide gear ratio spread, contributing to both performance and efficiency.
Driving Characteristics
The GLC 300d Coupe offers a compelling blend of performance and comfort. The 269 hp and 550 Nm of torque provide ample power for confident acceleration and effortless highway cruising. The 0-60 mph sprint is achieved in approximately 6.1 seconds, and the car reaches a top speed of 249 km/h (154.72 mph). The 9G-TRONIC transmission is well-tuned, providing smooth and quick gear changes. Compared to the gasoline-powered GLC 300, the 300d offers superior torque at lower engine speeds, resulting in a more relaxed driving experience, particularly during overtaking maneuvers. While not as overtly sporty as the AMG variants, the 300d provides a more than adequate level of performance for most drivers. The mild-hybrid system contributes to a seamless power delivery and enhances fuel efficiency, especially in urban driving conditions.
Equipment & Trim Levels
The GLC 300d Coupe comes standard with a generous array of features. Interior appointments typically include premium upholstery (often MB-Tex or leatherette), a leather-wrapped steering wheel, and aluminum trim accents. The MBUX infotainment system with a large touchscreen display is standard, offering navigation, smartphone integration (Apple CarPlay and Android Auto), and a host of connected services. Standard safety features include automatic emergency braking, lane keeping assist, and adaptive cruise control. Optional extras include a panoramic sunroof, premium sound system, heated and ventilated front seats, and a head-up display. The Coupe body style generally emphasizes a more sporty aesthetic, with a sloping roofline and a more aggressively styled front and rear fascia.
Chassis & Braking
The GLC 300d Coupe utilizes a sophisticated chassis design focused on balancing comfort and handling. It features a four-wheel independent suspension system, typically with steel springs and adaptive dampers available as an option. The suspension is tuned to provide a comfortable ride while maintaining good body control. Braking duties are handled by ventilated discs on all four wheels, providing ample stopping power. The standard 4MATIC all-wheel drive system provides excellent traction in all weather conditions. The system is typically rear-biased, enhancing driving dynamics. The steering is a precise electric power steering system, offering a good balance of feel and assistance.
Market Reception & Comparison
The GLC 300d Coupe has been generally well-received by automotive critics. It is praised for its refined diesel engine, comfortable ride, and luxurious interior. The mild-hybrid system is also seen as a positive addition, enhancing fuel economy without compromising performance. Compared to the gasoline-powered GLC 300, the 300d offers significantly better fuel economy, making it an attractive option for drivers who prioritize efficiency. However, some critics note that the diesel engine can be slightly noisier than the gasoline counterpart. Against competitors like the BMW X4 and Audi Q5 Sportback, the GLC 300d Coupe holds its own, offering a compelling combination of luxury, performance, and technology.
Legacy
The OM 654 engine family, including the version found in the GLC 300d Coupe, has proven to be a reliable and durable powertrain. Mercedes-Benz has invested heavily in diesel technology, and this engine benefits from advanced emissions control systems. While diesel vehicles have faced increased scrutiny in recent years, the OM 654 remains a popular choice for buyers seeking a fuel-efficient and capable SUV. On the used car market, well-maintained GLC 300d Coupes are expected to hold their value reasonably well, thanks to their reputation for reliability and their desirable combination of features and performance. The integration of mild-hybrid technology further enhances the long-term appeal of this model.
