AMG has been tuning, building and developing V8 engines from day one, and among their most famous efforts is the 6.2 litre naturally aspirated unit that made its debut under the bonnet of the Mercedes-Benz CLK and CLS 63 AMG in 2006. Known as the M156, the engine would replace the older 5.4 litre naturally aspirated and supercharged V8s across the model range, delivering between 451 and 622 bhp depending on its application. It would even feature in the R-Class MPV.

Having already made its mark in the passenger car range, the engine would be reworked and given a new role as the centrepiece for AMG’s first ground-up standalone model: the SLS AMG. For use in the super sports car, the engine gained a dry sump lubrication system and a new name: M159. This powered the SLS in its gullwing coupé, roadster, GT and Black Series forms throughout its time in production, although a 13 year old Ken would take a look at the apparent space under the bonnet when visiting the AMG headquarters in Affalterbach and ask the very knowledgeable man guiding me around the one-off Indian Summer special variant: “It looks like there’s room for the V12 under this bonnet, what do you think?” The response was a chuckle, followed by “Never say never.” The knowledgeable man was Ola Kallaneius, then head of Mercedes-AMG, and now head of Mercedes-Benz AG.

The SLS became the platform for Mercedes-AMG’s return to GT racing, with the car being developed to fit the regulations of the GT3 category - gullwing doors and all. The SLS GT3 would take numerous wins worldwide, including the Bathurst 12 Hour, Dubai 24 Hour, Spa 24 Hour and Nurburgring 24 Hour races. However, the SLS AMG as a road car would bow out of production in 2014, to be replaced by a smaller, more affordable and more turbocharged car that would be a closer rival to the Porsche 911.

The motoring press at the time went into overdrive with the news that the last bastions of the naturally aspirated 6.2 litre V8 would be leaving production, with their replacements set to have a brand new 4.0 litre twin turbocharged V8. Forgetting that AMG had introduced the 5.5 litre twin turbocharged M157 engine in 2011, there were huge doubts that the new downsized unit could get anywhere near the performance and character of the much loved 6.2 litre unit. Those doubts evaporated the moment that the M177 and M178 were experienced under the bonnets of the new C 63 and AMG GT.

With the future looking turbocharged, and the need for the successful SLS AMG GT3 to be succeeded on the race track, work began on its replacement. Everyone expected the name to be as imaginative as the model that came before, and for the new engine of the road car to find its way under the bonnet, but only one of those things would prove to be true when the Mercedes-AMG GT3 was unveiled. Nestled up against the firewall was the 6.2 litre naturally aspirated V8. But how?

In short: the AMG GT wasn’t an all new car; it would be insane to develop a bespoke chassis, produce it for four years before throwing it in the bin and starting all over again - a relatively mainstream manufacturer would simply never recover its costs by doing that. With that in mind, the front-mid engine layout with dry sump lubrication, transaxle gearbox, carbon prop shaft and rear-biased (47/53%) weight distribution all make sense: they’re carryovers from the SLS AMG. 

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