Mercedes AMG GT: full engine details revealed

This peak power is available at 6,250prm, while assessing maximum torque requires as little as 1,750rpm and can be maintained right up to 4,750rpm. AMG insiders have
previously revealed the engine has the potential to develop even more power, but have so far refused to be drawn on just how far they plan to take it.

Mercedes is yet to confirm basic performance figures for the AMG GT either, although we now know the EU6 emissions standard-compliant eight-cylinder unit can manage up to 28.8mpg – a 7.4mpg improvement over the outgoing 6.3-litre naturally aspirated V8. 

Built by Mercedes’ AMG performance arm according to the “one man, one engine” principal, the new smaller capacity V8 weighs in at a minimum of 209kg and benefits from two turbochargers housed in a compact ‘hot inside V’ formation.

Mercedes AMG GT 4.0-litre V8 engine angle

As the name suggests, the turbos are not mounted on the outside of the cylinder banks as is conventional, but are actually housed inside the banked V layout, resulting in better weight distribution between the front and rear axles. This apparently also serves to improve cooling, and means the engine can be placed lower to the ground, reducing the car’s centre of gravity. 

Dry sump lubrication sees the engine drop a further 55mm, and combines with forged aluminium crankcase and pistons to further reduce weight and improve emissions. A low-friction piston ring package further reduces fuel and oil consumption.

Elsewhere, there are zirconium alloy cylinder heads, offering improved heat resistance, and the engine sits on active mounts, which monitor its position and adjust it accordingly to avoid upsetting the balance of the car. Rounding off the efficiency-minded features is an ECO stop-start function and alternator management system.

The all-new GT sports car will come with a fully variable exhaust system, too, allowing the driver to vary engine sound depending on mood and circumstance. Exhaust flaps either side of the rear silencer activate progressively depending on transmission mode, engine speed and power requirements. Lower down the rev range these remain closed, causing exhaust gases to flow through additional damping to mute the engine sound. Accelerating will progressively open the flaps until both allow the V8’s full grunt to escape unrestricted.

Following completion, Mercedes apparently subjected the 4.0-litre engine to an extensive testing programme, a process involving a range of climates and routes, from cold weather trials in northern Sweden and high temperature runs in Death Valley, to laps of the Nurburgring and stop-start driving during city rush hour.