It’s rediculously quick when you ask it to be, and relaxed when you don’t

An M6 is $ 20k cheaper. That’s a fairly important note. Important for Alpina, that is. That fact elevates this B6S above the status of just M6 alternative. It elevates it to something psychologically higher. It’s a dangerous line to tread, because inheriting the top rank – especially when it’s an M-graded spot – is no easy task. But then Alpina has never been phlegmatic about its cars, often producing BMWs capable of giving M-car drivers a fright.

The B6S isn’t any different. It overshadows the M6 where it matters, eclipsing the blue roundel car’s output by 23bhp and swelling up in torque by an impressive 171lb ft, with both peaks accessible lower in the rev range. But more on that later.

What is a little different at first is the questionable taste of the detailing. I counted 13 ‘go faster’ Alpina stickers and logos. And this gold, cream and green combination must be unofficially known in the Buchloe factory as ‘the Middle East special’. This doesn’t look like the usual discreet Alpina, whose cars have never had to shout about being equal to M-badged BMWs.

On the whole though, the styling is nicely judged, giving out an attitude of restrained aggression, with a diffuser flanked by four pipes, an added rear flick on the boot for downforce and the signature Alpina four-part, five spoke alloys.

Once you’ve settled into the comfortable, hand-stitched leather of the cabin, there’s a lot more to like. You look ahead past the two air vents on the carbon fibre bonnet that expels supercharged V8 heat, and the first thing that hits you is how civilised and docile the B6S feels. On those 20in, low profile Michelins – 255/35 at the front, 285/30 at the rear – the ride quality is remarkable. It absorbs bumps with ease and not once did I ever experience any surprising jolts. All the while, you have the accompaniment of a V8 growl, with a simultaneous rumble from the exhaust. They’re sounds which make themselves known, but never intrude.

Not even when you decide to change down through the pimple-like nodule on the back of the steering wheel and use all 530bhp. The B6S’s flat torque curve means the amount of grunt you get is directly related to how far you’ve depressed the accelerator. It charges hard, hurling itself forward at a rate that’s equal to an M6 in a straight line, but almost certainly faster out of slower bends, thanks to its instantly accessible power.

Speaking of bends, the B6S is mighty on that front, too. Using the Electronic Damper Control, you can minimise the float and travel in the back axle that you occasionally experience in the Normal ride setting. Press the Sport button, point it at a twisting road and the steering, which was dull and slow in town, now comes alive. There’s very little roll, a lot of throttle response, and through every corner, the B6S tracts itself keenly exactly where you ask it to.

In an everyday situation, with unpredictable roads, the B6S will gain ground over an M6 because it feels less nervous, more compliant over rough roads. The tyres feel firmly screwed to the tarmac, like there’s never a point where you get less than the full contact patch. The limit comes on gradually, with a slight chirrup from the front end that warns you you’ve reached the threshold. Should you run wide, a light brush on the brakes adjusts your line. It’s only when the wheels are fully loaded up and you hit a bump mid-bend when its composure is ever-so-briefly disturbed. Suppleness may have been predicted in a car based on a Grand Tourer, but it’s the equally impressive controlled ride at speed that surprises. This all leads to a predictable conclusion: that the B6S is a very complete car, and one that you’d happily live with every day, because it serves just about every purpose. It’s ridiculously quick when you ask it to be and relaxed when you just want to get home at night.

But does it justify itself over a similarly priced SL63AMG, for example? That is a question of taste. The more conservative, and those seeking discreet performance will be the ones who buy the Alpina. I just hope they don’t spoil it by festooning it with unnecessary badges and stickers.