Welcome to the world of AMG, purveyors of flabbergastingly powerful saloons and estates, which no one actually needs, but many, it appears, desire. It's a German thing; BMW has its M5, Audi its RS6 and Mercedes its E 63 S 4Matic+, which goes on sale with its slightly cheaper and less powerful sister, next March in saloon and estate forms. So think about an engine bay brimming with a twin-turbocharged, hand-built, four-litre V8 and inlet-charge coolers. The numbers are terrifying. In this £83,000 S model, the Borg Warner twin-scroll turbos boost up 1.5 Bar delivering 604bhp and 627lb ft of torque, which means a top speed limited to 155mph, 0-62mph in 3.4sec and a Combined fuel consumption of 31mpg - on test we scraped just 11.7mpg. It's the fastest AMG they've ever built and given its lairy predecessors, that's some claim. Hand over another £3,300 and after a driving course at Mercedes-Benz World at Brooklands, they'll yank the limiter up to 186mph, which is still limited since there's some doubt about tyre longevity for this 1.9-tonne saloon above that speed.
So far, so normal for AMG, the formerly independent motorsport tuning company from Affalterbach, Germany, which celebrates its half century next year. Specialising in Mercedes-Benz with gargantuan engines and performance, by 1999, Mercedes threw in the towel trying to compete and bought the company. These days AMG is a trim level as well as a series of top-shelf-material performance derivatives, but it's still fiercely independent. It's a measure of its expertise and dedication that the division is now in charge of all Mercedes V8 engine development.
So while the engine is based on Mercedes-Benz's production V8, it has enough motorsport-derived goodies to make it an authentic AMG product, such as a closed-deck block, slipper pistons, exhaust and turbos in the centre of the vee with inlets on the outside, and cracked connecting rods to add strength to the big-end bearings.