What is it? The Alfa Romeo 159 Q4 is the top-of-the-line 159, with a new 3.2-litre V6 and four-wheel drive. It is propelled by the replacement for one of the most sonorous recent motors of them all: the V6 that made its debut in the otherwise disgraceful Alfa 6 of 1980. The new 256bhp 3.2 V6 brings a touch of sophistication, with direct injection and continuously variable valve timing for all four cams and 32 valves. Better yet, this engine issues more than an echo of that old V6. There’s the same deep-chested roar when you demand big acceleration from low revs, and the same higher-pitched, lightly resonant warble at the top end, which now extends to 7200rpm. And it’s bolted into another mechanical confection with a reputation: an all-wheel drive system that is an evolution of that found in the legendary Lancia Delta Integrale. This is an entirely mechanical set-up whose self-locking Torsen centre diff divvies 57 per cent of the twist action to the rear wheels – and can vary the split anywhere from 22/78 front/rear to 78/22. The result should be enhanced chassis balance, and seamless torque transfers between axles, in contrast to the Haldex systems used elsewhere.What’s it like? The 159 is big and, like almost every modern car, heavy. So while it feels brisk and covers ground fast, it’s no rampant tearaway. It’s to Alfa’s credit, then, that it has resisted decking it out with warpaint; in fact, only badges distinguish the Q4 from the 2.4 JTDm diesel. On the road, you feel very insulated aboard an immensely stiff shell, the seats cosset and you won’t hear much wind noise. There’s a bit of road roar on coarse surfaces, but that’s countered by a satisfyingly pliant ride, even on the biggest (18in) wheels. Some may reckon there’s a smidge too much roll, but this mild cushioning suits the car’s demeanour, especially as the brakes and steering aren’t the sharpest. The middle pedal might be progressive, but it feels frustratingly wooden. The steering will surprise those used to Alfa’s quick-acting racks, because it’s not terribly incisive or feelsome. It’s accurate, though, and once you discover how fast you can attack a series of S-bend swoops, you realise that the absence of twitchiness is a bonus. The Q4 is wonderfully fluent through bends, its line easily adjusted, its suspension well up to absorbing hard-hit bumps and camber changes.Should I buy one? A razor-sharp, rapid-reaction 159 will surely come – likely labelled GTA – but the fact that this isn’t it does not diminish the appeal of this highly capable, subtly cultured piece of kit. The Q4’s character is less obvious than in Alfas past, but it’s not short of depth.