Innovative oil supply and water cooling
Efficient oil delivery under all load and operating conditions is ensured by an oil pump with an electrically controlled compression stage. The oil pressure can be varied between 2 and 4 bar, which has advantages in terms of friction and fuel consumption. An extraction stage integrated into the oil pump for the two turbochargers prevents oil from being entrained into the charge air and exhaust gases, thereby helping to reduce emissions even further.
Both the sump and the extraction point have been optimised for maximum lateral acceleration and efficient lubrication. The oil capacity is 10.5 litres.
The combined water/oil cooling system represents an intelligent solution:
after a cold start, initially the engine oil is only cooled via the oil/water heat exchanger. If the cooling performance of the very compact cooler is insufficient, the flow is additionally directed through the external engine oil/air cooler by an oil thermostat. The advantage of this system is that the engine oil heats up more rapidly, as the engine coolant warms up more quickly and the oil is later cooled by the coolant. A selectable water thermostat ensures rapid warming of the coolant when starting the engine and driving off. Large intakes in the new front apron of the E 63 AMG ensure an effective flow of air to the water, engine oil, charge-air and transmission oil coolers.
The engine coolant is cooled using the particularly efficient cross-flow principle. There is a transverse flow of coolant through both the crankcase and the cylinder heads. Additional cooling slots in the cylinder head allow more efficient cooling of the combustion chambers, which entails advantages during combustion, enabling earlier ignition timings to be chosen without incurring the risk of knocking.
Generator management and optimised belt drive
The ECO start/stop function, which in “Controlled Efficiency” mode shuts down the eight-cylinder engine every time the vehicle is stationary, is not the only feature contributing to low fuel consumption. Generator management also helps to enhance efficiency: whenever the engine is on the overrun or when braking, kinetic energy is used to charge the battery rather than being wasted as heat in the usual way. In all other operating modes a combination of onboard network and generator management enables the generator to be kept at a low voltage. This reduces the load on the engine and makes for fuel savings of around
0.15 litres per 100 kilometres according to the NEDC standard, and up to
0.2 litres per 100 km in city driving with its frequent overrun and braking phases.
Highly efficient engine electronics for every function
All the engine functions are executed and controlled by a particularly efficient control unit. This state-of-the-art engine computer not only controls direct petrol injection, charge pressure, camshaft adjustment and variable oil supply but also communicates with all the other onboard control units, such as those of the AMG SPEEDSHIFT MCT 7-speed sports transmission. The microprocessor has more than 30,000 different parameters and functions stored in its memory, and is able to perform up to 260 million individual operations per second. To reduce the load on the engine control unit, the eight individual ignition coils have an integral electronic module on each cylinder. This ensures a strong ignition spark at all engine speeds and under all load conditions. The highly precise fuel distribution of the piezo-electric injectors is handled by eight high-voltage output stages.
Lightweight AMG sports exhaust system for a characteristic sound signature
The twin-pipe AMG sports exhaust system has a pipe cross-section of 70 millimetres from the manifolds to the rear silencers. The sound design is characterised by a perfect synthesis of tangible dynamism and hallmark Mercedes comfort on long journeys. Emotional appeal during acceleration and double-declutching combines with the appropriate restraint at steady speeds. A distinctive, signature AMG eight-cylinder sound emanates from the striking chrome twin tailpipes of the sports exhaust system.
Engine production – a tradition of hand-built excellence
Like all AMG high-performance engines, the biturbo eight-cylinder engine is assembled by hand in the hand-finishing section at AMG, observing the most stringent quality standards. Highly qualified engine fitters assemble the M 157 according to the philosophy “one man, one engine”. The signature on the characteristic AMG engine plate attests to the painstaking care exercised by the fitter.