Mercedes-Benz ML63 AMG

A small bus with a Trident missile attached to it

'Naffing fast': the Mercedes ML63 AM G

Price: £82,995
Engine capacity: 5.5-litre twin turbo V8 petrol
Power output (bhp @ rpm): 518 @ 5,250
Top speed (mph): 155
0-62 mph (seconds): 4.7
Fuel economy (mpg): 23.9
CO2 emissions (g/km): 276

You might not have noticed, but among the Chelsea tractors pulling up at school gates in some of the country's wealthier neighbourhoods, there are one or two oversized wagons that are just that little bit more ostentatious. They boast glitzy alloy wheels, carbon-fibre panels and gleaming Porsche, BMW and Mercedes badges. They are high-performance SUVs and they take the big, brash and borderline bonkers mentality of the standard SUV and strap a supercar's engine to it.

You might wonder why this is necessary. After all, most Chelsea tractors can already hit 60mph in less than eight seconds, but it turns out there are quite a lot of people (well, some Premiership footballers, rappers and oil sheikhs) who want to combine the up-on-high benefits of an SUV with the go really fast attributes of a supercar. Maybe they'd owned a Ferrari before the kids came along or perhaps they need to dash across Germany's autobahns every weekend. Anyway, if you don't like the idea of an £80,000 performance SUV with fuel economy to make Greenpeace weep, then the new Mercedes ML63 AMG isn't for you. If you're able to suspend your critical faculties though, this sports wagon is really something to behold.

Outside it gets all the standard bells and whistles from AMG – the Mercedes performance sub-division – but it's when you hit the chrome starter button that you hear why this car is different from the standard M-Class SUV. It gets a 5.5-litre V8 turbocharged petrol engine that roars into life with a growl and turns out enough power to propel it to 60mph in less than five seconds and to licence-endangering speeds a few moments after that. The only way I can describe it is that Mercedes has taken a small bus (with acres of leather and a host of gadgets) and fitted a Trident missile to the back of it. And all this power means it's only a second slower getting to 60mph than McLaren's new 12C Spider supercar. Unlike the supercar, though, it weighs more than 2.5 tons, so driving it fast requires the ability to suspend the belief that you're not going to plough a heap of precisely engineered German metal into a crash barrier. In short, it's naffing fast and designed for hooliganism on a grand scale.

It gets an "active curve system" from the boffins at Affalterbach that uses anti-roll bars that stiffen and move to do their damnedest to stop the tall body rolling around in fast bends. It works surprisingly well and you can, if you have the kahunas, cover bendy B-Roads at pace. Other than the vast speed on tap and the V8's exhaust warble, there's not much to draw you into the act of driving the ML63 hard, though. Sure, it's blistering pace-wise, but it's just too big and fast to push on public roads.

All this performance comes with an environmental price. Mercedes has worked hard to make the ML63 "greener", but it still pumps out 276g of C02 for every kilometre. The fuel economy is a joke and driving it into town to be collected felt like an environmental crime. The Arab princelings and footballers who'll buy it won't care though; it's a magnificent piece of kit, put together just to show how fast an off-roader can go. Aston Martin, Bentley and Jaguar all have plans on the drawing board for super-vast SUVs, so the demand is obviously there. For the super-rich at least, going fast is about to get a lot bigger.