| First Drive | Banbury, England | Alpina D3 Bi-Turbo |
Key Facts
Pricing: £46,950
Engine: 3.0-litre in-line six-cylinder twin-turbodiesel
Transmission: rear-wheel drive, eight-speed automatic
Body style: four-door saloon
Rivals: BMW 330d M Sport
CO2 emissions: 139g/km
Combined economy: 53.2mpg
Top speed: 173mph
0-62mph: 4.6 seconds
Power: 350hp at 4000rpm
Torque: 700Nm at 1500- to 3000rpm
In the Metal: 
Something of a connoisseurs' choice in the world of BMWs, the Alpina D3 Bi-Turbo could go unnoticed to all but the most well-informed car spotters. The most obvious signifier - apart from the Alpina script on the front splitter - are its 19-inch wheels. They're signature Alpina, the thin, multi-spoke lightweight rims an unmistakable tell-tale. The badging on the back helps too, as does the revised aero kit, including a more prominent boot-mounted spoiler. If you're left in any doubt, the quad tailpipes slung out underneath reveal this isn't an ordinary BMW, but one that's spent a good deal of time being honed to deliver a little more.
That's obvious inside too, from the Alpina badging, blue instruments, Alpina wheel, leather seats and numbered build plaque; the D3 Bi-Turbo is pleasingly different. Only the odd button shifters on the back of the steering wheel - in place of regular paddles - frustrate, in what's otherwise a pleasantly, if mildly, different spin on the 3 Series' interior.
Driving it:
The BMW 330d that the Alpina D3 Bi-Turbo is essentially based on is already an epic all-round car, but Alpina's comprehensive re-working has made it even more so. It's built on the same line as the M cars, before Alpina takes it off BMW's hands, the additional fettling creating a car that's pretty much peerless in its class. The engine, which gains a pair of faster spooling variable geometry turbochargers, a heavily revised intake system and new intercooler and a bespoke exhaust system, delivers 350hp at 4,000rpm and peak torque of 700Nm between 1500- and 3000rpm. It's that torque that dominates the experience, while a revised version of ZF's eight-speed automatic transmission gives plenty of ratios to keep it in its sweet spot - the way the D3 Bi-Turbo gathers pace is genuinely momentous.
The gearshift works brilliantly enough in automatic mode, but shifting the ratios manually really allows that mid-range grunt to be enjoyed, so it's a shame then that the Alpina forgoes conventional paddles and instead uses buttons mounted on the back of the wheel. The steering wheel itself wears an Alpina badge, though you don't need that to tell you this is no ordinary 3 Series; it's the response and feel. Revised electronics, as well as chassis revisions to suit the 19-inch Alpina wheels, utterly transform the feedback at the wheel. There's genuine feel at the rim, while the response is crisp and incisive, quite removed from the rather lifeless, if accurate steering on offer from its BMW relation.
Those chassis revisions have been revelatory in the D3's ride, its ability to smother even pockmarked British roads is remarkable. That ride comfort and composure have been achieved despite spring rates that are 40 per cent stiffer all round, Alpina's attention to detail going so far as to work with Michelin to create run-flat tyres with softer sidewalls to allow that ride quality. Optioned here with a limited slip differential, that quick steering, mighty engine response and revised DSC and DTC systems with a benign transition from grip to slip allow you to reach and breach the D3's limits at will. That means every corner can be exited on demand with any degree of corrective lock at the wheel you like. It's no hooligan though, the D3 Bi-Turbo is just obviously rear-driven, very entertainingly so when the mood takes you.
What you get for your Money:
All that power doesn't come at the expense of economy, as the D3 Bi-Turbo returns 53.3mpg on the official combined cycle and emissions of 139g/km. That makes it about one of the most cost effective performance cars you can buy on company money, while keeping a relatively low profile in the car park.
Worth Noting
Alpinas are officially recognised by BMW, sharing warranty coverage since 1964, despite being registered as an automobile manufacturer in its own right since 1983. The D3 is built on the same line as BMW's M cars, before Alpina finishes them at its own facility. They're very exclusive too: Alpina UK has sold around 60 so far this year. The D3 Bi-Turbo is also available as a Touring (estate) model.
Summary
It would be easy to dismiss the Alpina D3 Bi-Turbo as a curious anomaly for buyers craving exclusivity, but the thoroughness of the engineering is obvious from the first second you drive it. The engine is mighty, but more than that the chassis and transmission revisions complete what is a hugely competent, well-rounded package. That it'll slip under the radar of all but the most dedicated enthusiasts is part of its appeal, too, the D3 Bi-Turbo the ultimate sleeper. We'll have a de-badged Touring for even more stealth please...
