Mercedes-AMG has long been synonymous with high-performance vehicles, and their latest masterpiece, the AMG 4.0-liter V8 biturbo engine, firmly cements this reputation. This groundbreaking engine is the beating heart of the new Mercedes-AMG GT, showcasing a revolution in engine design and technology. It’s an embodiment of sublime power delivery, lightweight construction, exceptional efficiency, and environmental consciousness, all packaged into one potent unit. Producing up to a staggering 503 horsepower and 479 lb-ft of torque, this new AMG V8 engine delivers motorsport-inspired performance, setting a new benchmark in the realm of Biturbo Mercedes engineering. This engine not only continues the legacy of powerful V8s that began with the iconic M100 in the 1967 300 SEL 6.8 AMG racing car but also pioneers trendsetting features that point towards the future of high-performance powertrains.
AMG, the performance division of Mercedes-Benz, has always been revered for its powerful V8 engines. The Affalterbach facility is the birthplace of innovative and exhilarating high-performance engines, where Mercedes-AMG GmbH takes full responsibility for both the development and production processes.
Tobias Moers, Chairman of the Board of Management of Mercedes-AMG GmbH, aptly stated, “V8 engines are an integral part of the AMG philosophy and the brand’s commitment to ‘Driving Performance’. The V8 biturbo Mercedes engine for our new GT is going to delight our customers!”
Christian Enderle, Head of Engine and Powertrain Development at Mercedes-AMG, added, “The new AMG 4.0-liter V8 biturbo sees us presenting an exciting and powerful sports car engine which, thanks to a number of measures, also represents the next step in efficiency.”
The Innovative ‘Hot Inside V’ Configuration and Dry Sump Lubrication System
This new AMG V8 engine features a revolutionary design with two turbochargers positioned not on the exterior of the cylinder banks, but nestled within the V configuration itself – a design known as ‘hot inside V’. This innovative approach offers several key advantages: a more compact engine architecture, optimized responsiveness to throttle inputs, and reduced exhaust gas emissions. Furthermore, the integration of dry sump lubrication allows for a lower engine installation, effectively lowering the vehicle’s center of gravity. This lower center of gravity is crucial for achieving enhanced handling and higher lateral acceleration, vital characteristics for a high-performance sports car. The M178, as it’s internally designated by AMG, stands as the world’s first sports car engine to combine the ‘hot inside V’ configuration with dry sump lubrication. Remarkably, with a dry weight of just 460 lbs, this AMG V8 is also the lightest engine in its competitive class, further enhancing the agility and performance of any biturbo Mercedes vehicle it powers.
AMG M178 V8 engine showcasing its compact design and advanced engineering.
AMG M178 V8 Engine: Key Specifications
| Feature | Specification |
|---|---|
| Cylinder Arrangement | V8 |
| Cylinder Angle | 90° |
| Valves per Cylinder | 4 |
| Displacement | 3982 cc |
| Bore x Stroke | 83.0 x 92.0 mm |
| Cylinder Spacing | 90 mm |
| Compression Ratio | 10.5 : 1 |
| Peak Output | 503hp (375 kW) @ 6250 rpm |
| Specific Output | 126.3 hp/liter (94.2 kW/liter) |
| Maximum Torque | 479 lb-ft @ 1750 – 4750 rpm |
| Specific Torque | 120.4 lb-ft/liter |
| Maximum Engine Speed | 7200 rpm |
| Maximum Charge Pressure | 17.4psi |
| Engine Weight (Dry) | 460 lbs |
Motorsport-Inspired Performance and Unmistakable AMG V8 DNA
The AMG M178 engine is engineered to deliver superior power with a motorsport-derived responsiveness. It produces an emotionally resonant and instantly recognizable AMG V8 engine sound, coupled with rapid response and substantial pulling power across the rev range. The torque curve is optimized for exceptional driveability, with the peak torque of 479 lb-ft readily available from 1750 to 4750 rpm. This broad torque plateau ensures effortless acceleration and dynamic performance in all driving situations, a hallmark of the biturbo Mercedes experience.
Sharing a technological lineage, the 4.0-liter V8 shares design principles with the AMG 2.0-liter turbo engine found in models like the CLA45 AMG and GLA45 AMG. Notably, both AMG engines share the same bore/stroke ratio, a design characteristic that contributes to their high-revving capabilities and energetic performance. The engine utilizes third-generation direct petrol injection with piezo injectors for mixture formation, further enhancing the efficiency and economy of this potent AMG 4.0-liter V8 biturbo power unit.
Advanced Materials and Technologies for Enhanced Durability and Efficiency
The aluminum crankcase, manufactured using sand casting technology, features a closed deck design. This construction method provides exceptional strength and rigidity while minimizing weight. The cylinder bores are treated with NANOSLIDE® technology, a Daimler innovation that renders them twice as hard as conventional cast-iron linings.
NANOSLIDE®, pioneered by Daimler starting in 2000 and implemented in over 200,000 engines since 2006, was first utilized in an AMG V8 engine – the predecessor to this new 4.0-liter biturbo, highlighting AMG’s continuous pursuit of innovation. This award-winning technology’s application has expanded, and it is now also utilized in the Mercedes F1 V6 turbo engine since the 2014 race season, demonstrating its proven performance in the most demanding environments.
NANOSLIDE technology applied to cylinder liners, enhancing durability and reducing friction in the biturbo Mercedes engine.
‘Spectacle honing’ is another technique employed to minimize friction and improve fuel efficiency. In this intricate process, the cylinder liners undergo mechanical surface treatment after being bolted into place. A jig, resembling spectacles, is affixed to the crankcase, simulating the cylinder head mounting. This allows for the compensation or elimination of cylinder distortion that might occur during final assembly, resulting in enhanced durability and reduced oil consumption. The new AMG V8 also incorporates forged aluminum pistons, which are lightweight yet high-strength. A low-friction piston ring assembly further contributes to reduced fuel and oil consumption, maximizing efficiency in this biturbo Mercedes powertrain.
Dry Sump Lubrication for Superior Dynamics
The implementation of dry sump lubrication eliminates the need for a conventional oil pan. This allows the engine to be positioned 2.2 inches lower within the spaceframe, significantly lowering the vehicle’s center of gravity. This lower center of gravity is paramount for a sports car designed for exceptional lateral dynamics. Beyond improved agility, dry sump lubrication ensures consistent and direct oil extraction from the crankcases, guaranteeing optimal engine lubrication even under extreme lateral forces experienced during high-speed cornering. This robust lubrication system is critical for maintaining engine health and performance under demanding driving conditions in a biturbo Mercedes.
The M178 dry sump lubrication system utilizes a suction pump, a pressure pump, and an external oil tank with a 12-liter capacity. The system circulates a total of nine liters of engine oil. The oil suction pump extracts oil directly from the crankcases, cylinder heads, and valve body assembly, delivering it to the external oil tank at a rate of up to 250 liters per minute. The lubricant resides in the external tank for a mere five seconds before being recirculated through the high-performance engine. Efficient engine oil extraction further contributes to improved engine efficiency. The pressure oil pump’s on-demand control adapts to engine rpm, temperature, and load, optimizing performance and efficiency. The oil pan bottom section and oil tank are constructed from plastic, reflecting a commitment to lightweight construction.
Advanced Cylinder Heads and Fuel Injection
The cylinder heads of the AMG 4.0-liter V8 biturbo Mercedes engine are manufactured from a zirconium alloy, chosen for its exceptional temperature resistance and thermal conductivity. Four overhead camshafts control a total of 32 valves. Camshaft adjustment on both the intake and exhaust sides optimizes engine response and gas exchange across various operating conditions. Optimized valve springs and a low-friction valve gear with cam followers further enhance fuel efficiency.
Direct injection with spray-guided combustion, combined with biturbocharging, maximizes thermodynamic efficiency, resulting in reduced fuel consumption and lower exhaust emissions. High-speed, precision piezo injectors directly inject fuel at high pressure into the eight combustion chambers. Multiple injections occur on demand, ensuring a homogenous air-fuel mixture for optimal combustion. Fuel delivery is electronically controlled and fully variable, with fuel pressure ranging from -1450psi to 2,900psi.
‘Hot Inside V’ Biturbocharging and Performance Exhaust
In a departure from conventional designs, both exhaust gas turbochargers in the new M178 engine are positioned within the ‘hot inside V’ configuration, rather than externally. This layout results in a significantly more compact V8 engine, which facilitates optimal weight distribution between the front and rear axles and allows for a lower engine mounting position. The ‘hot inside V’ design also optimizes airflow to the turbochargers. Electronically controlled blow-off valves ensure immediate and direct engine response. The maximum charge pressure reaches 17.4psi, and the turbochargers can spin at up to 186,000 revolutions per minute. This forced induction system effectively increases the amount of oxygen in the combustion process, significantly boosting power output for this biturbo Mercedes engine.
The ‘hot inside V’ configuration of the AMG biturbo engine, showcasing the compact turbocharger placement.
Two firewall catalytic converters, constructed from thin-walled ceramic material and positioned close to the exhaust gas turbochargers, ensure rapid emission control response. Combined with two metal, underfloor catalytic converters, the M178 engine delivers effective emission management, meeting stringent environmental standards.
The sports exhaust system with fully variable exhaust flaps is a key element in the emotive appeal of this biturbo Mercedes engine. This system allows the driver to modulate the engine sound, selecting between a comfort-oriented, subdued tone for relaxed cruising and a more aggressive, motorsport-inspired sound for spirited driving. The exhaust flaps, located on either side of the rear silencer, are variably actuated based on transmission mode, driver input, and engine speed. At low loads and engine speeds, the flaps remain closed, directing exhaust gases through a longer, more muffled path. During acceleration, the flaps progressively open, and under full load at higher engine speeds, both flaps are fully opened, unleashing the full, powerful AMG V8 sound.
Advanced Cooling Systems for Peak Performance
For sustained peak performance, even in high ambient temperatures, Mercedes-AMG employs indirect air/water intercooling. The charge air cooler utilizes a separate, low-temperature water circuit. Optimized flow within the intercooler ensures that intake air temperatures are kept below 356 degrees Fahrenheit. The low-temperature cooler, with its dedicated water circuit, effectively cools the compressed intake air before it enters the combustion chambers, maintaining consistent intake temperatures even under demanding conditions. A large radiator at the front of the car ensures efficient cooling of the water circulating in the low-temperature circuit. Extremely short charge-air ducts contribute to optimal engine responsiveness.
The engine coolant system utilizes a highly efficient cross-flow principle and a three-phase thermostat for rapid coolant warm-up. The water pump, driven by a timing chain rather than a conventional poly-V-belt, simplifies the belt drive system and reduces drive power losses. With a rated flow of 111 gallons per minute, the water pump can circulate a substantial volume of coolant, ensuring effective thermal management.
An external engine oil cooler, positioned in the front apron of the Mercedes-AMG GT, further aids in heat management for the V8 engine. A two-stage, controlled oil pump regulates engine oil circulation, varying flow rate based on load and engine speed, optimizing fuel economy. At high engine speeds, over 1.0 quart of engine oil per second flows through the oil lines and ducts. Weight reduction is achieved through the use of aluminum for numerous oil and water lines.
Sophisticated peripheral systems further enhance the engine’s performance and efficiency, including:
- Separate cooling-air flow for the exhaust gas turbochargers to manage high thermal loads.
- Active engine mounts to balance dynamic performance and ride comfort.
- Efficient auxiliary units driven by two short, low-friction belts.
- A two-mass flywheel with centrifugal pendulum to minimize torsional vibrations for smooth operation.
- ECO start/stop function and alternator management for fuel efficiency.
Rigorous Testing and “One Man, One Engine” Philosophy
AMG engines undergo rigorous testing at nine high-tech test stations in Affalterbach. These stations can simulate a wide spectrum of driving conditions, from cold starts to mountain passes and high-speed track driving, pushing engines beyond 630hp and 738 lb-ft of torque to their limits. Function and endurance bench testing are crucial for verifying the performance and durability of all engine components. New AMG engines endure thousands of hours of endurance testing to ensure the highest quality standards throughout their operational life.
Extensive practical trials are conducted across diverse climatic zones, from arctic Sweden to the deserts of Death Valley, and on demanding tracks like the Nürburgring Nordschleife and high-speed circuits. This comprehensive testing program ensures the day-to-day practicality, reliability, and long-term durability of each new generation of biturbo Mercedes engines.
The AMG 4.0-liter V8 biturbo engine is meticulously hand-built in Affalterbach following the “one man, one engine” principle. Highly skilled technicians assemble these high-performance engines by hand, adhering to the strictest quality standards. The technician’s signature on the AMG engine plate serves as a testament to this exclusive production method, signifying peak quality and the transfer of technology from motorsport, from Formula 1 to customer racing programs.
An AMG engine technician assembling a biturbo Mercedes engine, adhering to the “one man, one engine” philosophy.
A Legacy of Powerful AMG V8 Engines
Powerful eight-cylinder engines are deeply ingrained in the history of Mercedes-AMG. Since its establishment in 1967, AMG has consistently delivered high-performance V8 vehicles. The 300 SEL 6.8 AMG, which achieved a class victory and second place overall at the 1971 24-hour race at Spa-Francorchamps, marked an early milestone. Based on the Mercedes-Benz 300 SEL 6.3, the racing saloon’s engine output was boosted to 422hp, making it a sensation.
The M117 engine, AMG’s first eight-cylinder unit with a four-valve-per-cylinder design, was another significant engine. In 5.6-liter form, it propelled the 300 CE 5.6 AMG to a top speed of 188mph in 1987, earning it the “The Hammer” nickname in the US. The supercharged AMG 5.5-liter V8 of 2001, the M113 K, and the even more potent supercharged 5.5-liter V8 in the SLR McLaren (M155) further solidified AMG’s V8 leadership. The naturally aspirated 6.3-liter V8 (M156) in 2005 and the 5.5-liter V8 biturbo M157, renowned for its efficiency, continued this powerful lineage.
The new AMG 4.0-liter V8 biturbo engine represents the latest chapter in this ongoing story of high-performance V8 innovation. It is a testament to Mercedes-AMG’s unwavering commitment to “Driving Performance” and the future of the biturbo Mercedes legacy.
