Accessible torque is something the BMW Alpina has long since traded on, and it has always made for a fairly stark contrast with M division’s official go-faster saloons, which were fitted with high-revving atmospheric engines – until recently, at least.
Alpina’s twin-turbo solution makes this car smooth and responsive at low revs, when the smaller compressor is providing the boost. There is very little softness in the accelerator pedal – just precision and proportionality. Which is to be expected from a company that knows the value of driveability in a road car.
So when you ask for 40 percent of engine performance, that’s exactly what you get, and you get it pretty smartly – unlike some high-output turbo engines, where it’s as if you have to ask for 60 percent before feathering the accelerator to get the desired 40 percent.
The true pace of the B3 is better reflected by in-gear acceleration than the standing-start numbers we recorded. The 30-70mph dash can take as little as 4.2sec in third gear, a still-muscular 5.3sec in fourth and 7.3sec in fifth.
This is instant, generous, real-world speed of the ‘no sooner said than done’ variety. If you put the gearbox in manual mode, the B3 feels brisk largely irrespective of gear, across a broad speed range. But left in ‘D’, the accelerative experience is even more convincing. The ZF eight-speed auto brilliantly makes the most of that pulling power, upshifting as and when you’d want it to and only kicking down when you expect.
The price to be paid makes itself known the instant the bigger of the two turbos comes on boost and peak torque is delivered. At full throttle, this happens in a slightly unceremonious rush that’s in conflict with the smoothness of the engine’s delivery everywhere else.
You could say it adds drama, and on the track it’s possible to drive around the problem most of the time. But not always. And we’d prefer to know exactly when 443lb ft is going to turn up rather than having to guess.