When it was launched towards the end of 2002, the Cayenne attracted prophets of doom like wasps to a half-eaten jam sandwich. Analysts, journalists, 911 purists, people who just like to moan – everyone had their doubts. I was one of them.

A number of things worried us. One, Porsche was a maker of sports cars, pure and simple; the Cayenne might just turn out to be a monstrous mistake. Two, a 4x4 with virtually supercar grunt – which the turbocharged V8 flagship genuinely delivered – was the answer to a question no one had asked. And three, the Cayenne wasn’t just ugly but a ghastly caricature that, unforgivably, grafted elements of the hallowed 911 onto a bulky carcass of such asinine dullness that it demeaned the very essence of the legendary marque.

But while many of us predicted trouble ahead, Porsche resolutely faced the music and danced. Not only was the Cayenne not a flop, it wildly exceeded Porsche’s expectations: the company planned to sell 20,000 worldwide each year, but sales have been almost double that level.

At a glance, the second generation Cayenne – launched, not coincidentally you might suppose, just a few months after BMW’s revised X5 – doesn’t look vastly different. But the overall effect of the revised bumpers and lights succeeds in giving the SUV a sharper, lighter, more muscular look that disguises the bulk well.

The mods are more than merely cosmetic, of course, and contribute to a slightly smoother passage through the air. There’s even a rear diffuser – surely a first for a part-time off-road vehicle. The biggest changes, though, are under the skin and, in particular, under the bonnet, where the Cayenne gets a new range of direct-injection petrol engines (V6, V8 and V8 biturbo, as before) that claim improved responsiveness, power and economy.

The other big news is the debut of Porsche Dynamic Chassis Control, an active hydraulic anti-roll bar system that keeps the body flat and the tyres firmly planted on the black stuff in brisk cornering and on bumpy surfaces.

With a whopping 50 more horsepower than before – up from 444 to 494bhp, still at 6000rpm – and an equally impressive torque peak of 516lb ft at 4500rpm, the Cayenne Turbo is suitably revitalised to take on that other supercar-baiting SUV, the Mercedes ML63 AMG, and claims 0-62mph in 5.1sec and a top speed of 171mph. As before, power is split 38/62 front/rear, though the multi-disc clutch can direct up to 100 per cent of drive to the front or rear as required.

In addition to PDCC, the Cayenne Turbo gets Porsche Active Suspension Management (PASM) with air suspension as standard. The love affair with abbreviations also extends to Porsche Stability Management (PSM), with its brake assist function, and ABS that works as effectively off road as it does on.

All of which makes the Cayenne Turbo an even more supernaturally gifted all-rounder than it was before. On the open road it can run with supercars; on nature’s organic gloop it’s virtually unstoppable. Indeed the new Cayenne Turbo appears to have the drop on physics itself. It accelerates with barely believable ferocity, lunging imperiously through 120mph on its way to even more outrageous supercar-goading feats. The sensation is truly surreal, the sense of speed diluted by the lofty driving position; in fact it’s so deceptive you tend to arrive at bends travelling much faster than you think, even when fully acclimatised.

But here’s the most impressive thing of all. While the majestic poise and deftly disguised mass of the old Cayenne Turbo would degenerate into messy, scrubby understeer once the prodigious grip finally ran out and the traction electronics kicked in, the new one simply refuses to get ragged unless you attempt insanely ambitious cornering speeds. And even if the massive brakes do eventually start to wilt if you go at it hard enough for long enough, the new Cayenne Turbo still manages to lop a remarkable five seconds from the old car’s time around the Nürburgring.

In the old Cayenne, the novelty of pushing the envelope palled quickly. Not so the new car. It’s a whole lot of fun to punt through the twists, and that’s something I never thought I’d say about a Cayenne. It’s still amazing how rapidly the fuel gauge needle heads west, but it seems that Porsche has had the last laugh again.