Mercedes-Benz's new E63 AMG

It wasn't too long ago that car makers were talking of dialling down the monstrous power outputs that had become prevalent in the industry, mindful of clampdowns on speed and emissions and a general shift towards lower impact, more economically minded motoring. These shifts are presumably still in the offing, as there is no immediate sign of the high performance big guns calling a ceasefire. Mercedes' new E63 is a case in point. AMG has evolved from an independent tuning company to a core Mercedes subsidiary, a highly profitable tranche of the business devoted to turning out swift and bespoke variants of the company's core production models.

Now it's the turn of the new E-class, launched earlier in the year and hailed as a return to the company's engineering-led values of old. The new model is certainly robust, the physical solidity of the structure paired with Mercedes' angular new design language. Inside, this works brilliantly, but the exterior isn't quite the same roaring success, certainly at the rear. While the front end, with its slit headlights and deep spoiler, looks suitably muscular and brutish, the car suffers from a thickening around the midrift that unbalances the proportions, creating a slightly adipose profile out of what could have been a pitched-forward, poised stance.

Behind the wheel is an empowering place to be. However, as in many modern cabins, thick, motor-filled seats, airbag-stuffed pillars and centre consoles containing cubby holes and air vents all conspire to rob the passenger of any excess wriggle room; you're never exactly short of space, but you do feel slightly pinned to your seat. If the driver is making full use of AMG's engine-building skills, this limited movement is no bad thing, as the g-forces can give unwary passengers a bit of a pummelling. The E63's 6.3 litre V8 puts out 518 bhp through the rear wheels: dial all the electronic controls up to their most performance-focused settings, and the E63 will happily chew through tires and push itself through corners at unfeasible speeds. Strip away the engine de-limiter and the car would be good for 175 mph, not bad for a car with space for five people, a generous boot and a full compliment of onboard equipment.

It's hard to see where AMG can go from this kind of benchmark, although with each new model the specialists seem to eke out ever higher figures. In practice, fuel consumption and emissions are also being improved, but these gains are effectively negated if you start dipping into the power the E63 has to offer. Still, it's a very pleasant way of hovering up long distances. Extensive interior spec (and a long option list) means allowances for iPods and DVDs, a nifty but somewhat uncalled for night vision function that 'sees' further than the human eye along dark country lanes, and all-electric functionality for just about everything else. When the estate version of the E63 arrives it'll throw in even more functionality – together with more potential for pulverising loose objects, luggage and pets when the road gets twisty.

Come 2012 and all this fossil fuelled testosterone might finally be on the wane as AMG rolls out the all-electric version of its SLS supercar, a car that promises slingshot acceleration and race car handling. Perhaps the electric SLS and its competitors will usher in a redefinition of power, a renewed emphasis on efficiency and perhaps even an end to the tyranny of the unattainable top speed as the industry's ultimate merit badge.