A brand synonymous with creating transcendent V8s, Mercedes-AMG’s guttural 4-litre biturbo M178 is a hand-built masterpiece that never fails to propel passengers into a state of giddiness, whether applied in a Mercedes-AMG GT, GT S, or Aston Martin DB11.
In the judges’ scoring, the OEM’s eight-cylinder bested Porsche’s 4-liter boxer by a relatively narrow margin but beat BMW’s M three-litre twin-turbo six-cylinder hands down.
Innovation lies at this engine’s heart, where two turbochargers
are mounted on the inside in a ‘V’ configuration, rather than on the outside as has traditionally been the case. It’s the first sports car engine to feature this ‘hot inside V’ feature and dry sump lubrication, which offers the benefits of a more compact design and can be installed lower in the car for a more road-hugging centre of gravity and greater lateral dynamics. The system also ensures an optimum amount of fresh air to both exhaust gas turbochargers, as well as electronically controlled blow-off valves, delivering a highly precise performance where 2.3 times more oxygen atoms are channelled into the turbocharged engine than would be the case in an atmo.
The result is motor racing level performance with an output range from 468PS to 517PS with the block in the Mercedes-AMG GT S pushing 163Nm of torque per litre for a white-knuckle maximum of 650Nm at 6,250rpm. All from a lightest-in-its-class block weighing just 209kg.
But power is just one facet of this V8’s appeal – its notorious snarling soundtrack is also an essential (and expected) element of the experience, which doesn’t disappoint. Here, the M178 engine has been specifically engineered with its own distinctive tonal notes for the GT, notes that can be physically felt when the exhaust flaps open under full load.
John Carey, who writes for Cars Guide in Australia, claims, “The 4-litre twin-turbo V8 from Mercedes-AMG is a versatile beast, at home in everything from an SUV to GT.” And we couldn’t agree more.