The badge reads Porsche, the heritage is sports car yet the body is the size of a small terrace.

After years of honing pretty much one model Porsche had a corporate rush of blood and developed an off-roader sized 4x4.

The result was the Cayenne and this is the latest incarnation.

Exterior changes are subtle with new front and rear ends. At a glance it's still easily recognisable as a Cayenne, albeit slightly tidier and more appealing.

Turbo gets the huge front airdams, intakes and radiators. It also gets quadruple tailpipes to differentiate it from the V6 and normally-aspirated variants.

Big red shiny Porsche brake callipers peer through the massive alloy wheels, the first hint, after the badge, that this is a car built for on-road performance rather than muddy terrain. And what performance!

New Turbo boasts a gargantuan 500bhp from its big 4.8 litreV8, enough to propel this monster truck to 60mph in under five seconds and on to a ridiculously high top speed of 171mph, a staggeringly high figure for a normal 4x4. But then there is nothing normal about the Cayenne. It is in every way a pumped up Porsche, a macro sports car.

It performs like a sports car, it handles like a sports car but it is so much more practical than a sports car.

Observers might look on in bewilderment, questioning the rationale behind such a beast. But if you think about it the Cayenne does make perfect sense.

Your average Porsche sports car - if there can indeed be an average Porsche sports car - performs beautifully. But where do you put the kids, granny, the mountain bikes, the luggage, the shopping? Indeed you need a second, more practical, car for most occasions and the 911, Caymen or Boxter would spend more time under the dust sheet.

Cayenne Turbo solves all these problems by being two cars in one, so even at about £75,000 it's actually good value, honestly!

The 4x4 drivetrain and extra ground clearance means you can venture off the hard stuff.

There's even a little mountain sign on the transmission tunnel, so it must be an off-roader.

There are further switches offering the options of comfort, normal and sports, altering the ride and damping.

Paddle shift on the steering wheel changes the stunningly good six-speed automatic gearbox.

Otherwise the Cayenne is just a big, old capable sports car with monumental amounts of power and indecently good handling and driveability for this class of car.

It's a mad automotive world that we live in but the Cayenne seems to make sense of it all.