At first glance, it would be easy to mistake the grand touring Alpina B4 S coupe for just another BMW 4 Series.
On the surface, there’s not much to set it apart from a regular 440i coupe. Keen-eyed BMW fans will immediately clock the subtle front lip, heckspoiler rear lip, multi-finned alloy wheels, and quad-tipped exhaust, but unlike a pumped-up M4 and its parade of unique panels, the B4 S mostly flies under the radar.
While it might be visually similar to a regular 4 Series (and a Luxury Line at that, not the sports-styled M Sport), beneath the surface Alpina’s take on things lifts the powerful coupe beyond the already impressive stats of BMW’s own.
The starting point is the six-cylinder 440i, but whereas BMW’s factory figures settle at 240kW and 450Nm, Alpina pushes out a more prodigious 324kW and 660Nm, meaning the B4 S outguns a standard 317kW M4 and sits right on the tail of the 331kW Pure and Competition, while shading the M range’s 550Nm.
Those figures might look like a fair fight, but delve a little deeper and whereas the Alpina’s 6250rpm power peak is in the vicinity of the M4’s 7000–7300rpm max (depending on the model), torque figures tell a very different story.
You can have all of the M4’s thrust between 1850 and 5500rpm, but the B4 S makes you wait until 3000rpm and uses a smaller slice of the rev range, with torque figures washing off past 4500rpm.
In the same way you couldn’t simply take a high-speed Euro train, drop it onto Australia’s crumbly rail network and expect the same speed and efficiency, bringing the Alpina B4 S bahnstormer to Aussie streets creates an utterly frustrating user experience. Not because there’s anything wrong with the B4 S, more that Australia’s road and traffic conditions don’t favour its grand touring style. That’s a damn shame.
Long run-ups like freeway on-ramps are the perfect places for the Alpina to flex its muscle, but if you care to engage in the traffic light grand prix, opportunities are much more limited. The B4 S is hardly a slug, but the off-the-line urgency of an M4, or a standard 440i for that matter, just isn’t there.
Officially, Alpina claims 0–100km/h sprints will be done and dusted in 4.2 seconds against four seconds flat for an M4 Pure, but the rush really arrives in the latter part of that sprint, not the launch section.
The cruellest blow of all has to come in rolling acceleration, where Alpina’s coupe will fire like a slingshot should you nail the skinny pedal on a suitable stretch of road. Australia’s crippling repercussions for tipping even slightly over the posted limit makes doing so a foolhardy endeavour.
General drivability also takes a one-two hit thanks to that high torque band. Slip the B4 S into drive and expect to unlock that extra Alpina-developed performance and you simply won’t get it.
An M4 will feel eager, powerful, and ready to rumble from the moment you select drive. Meanwhile, a B4 will feel timid, cautious and generally unenthusiastic about behaving like a 300kW+ sports coupe – at least until you flick the transmission selector to the left to engage Sport mode.
Do so and the shift pattern changes from one that resolutely refuses to venture beyond 2200rpm, to one that simply won’t allow itself to dip below the 2000rpm mark. More revs mean more performance from the Alpina’s bespoke bi-turbo set-up, and suddenly the B4 S lives up to its $149,900 plus on-roads performance potential.
Does that make the B4 S an M4 rival then? No, not even close. Instead of lining up against angry fire-breathers like the M4, Mercedes-AMG C63 or Audi RS5, the B4 S has a more old-fashioned motoring set in mind and technically exists in a space of its own free of equal-price and equal-capability competitors.
Even with a set of massive 20-inch wheels, the Alpina delivers long-range comfort. Firm though it may be, the B4 S is never rough or rattly over chopped tarmac, and at freeway speeds the road-hugging dynamics make the romantic notion of cross-continental touring a distinct possibility.
Suspension is, of course, another area touched on by Alpina, from adaptive dampers to unique geometry and “subtle elastokinematic measures” to ensure a purpose-built handling feel without compromise to drivability from the added power and torque.
So, the Alpina B4 S is more of a competitor to cars built decades before it. Can’t afford a classic GT car from Maserati or Aston Martin? No worries – Alpina has you covered with its seemingly strange blend of relaxed athleticism and potential in reserve, with a new-car warranty to boot.
Inside, things are more akin to what you’ll find in a regular BMW, with a few special touches here and there. Merino leather trim in Kashmir Beige comes from the BMW Individual range, but the application of Alpina logos to the seats and inlaid in the dash wood is unique.
So too the non-M Sport steering wheel contrast-stitched in green and blue with peculiar little gearshift nubs (not even full-fledged buttons or paddles) tucked at the back of the rim. Odd, and absolutely Alpina-esque.
Given the otherwise relaxed composure of the B4 S, steering comes across as surprisingly alert. Throw it across a winding road and there is no end to the rewards the finely honed steering delivers while winding eagerly and rapidly from lock to lock.
The flipside comes on the freeway, where a sense of over-urgency just off centre makes keeping a steady straight-line course more work than it ought to be, requiring constant fidgety corrections.
BMW groups the Alpina B4 into the 4 Series’ Service Inclusive prepaid maintenance package, meaning three years’ servicing priced from $1495 for the ‘Basic’ oil, filters and fluids package or $3900 for the ‘Plus’ package that includes brake pads, discs and wipers over the same term. BMW’s three-year/unlimited-kilometre warranty also applies.
Aesthetically, the B4 S is one of the nicest interpretations of the 4 Series coupe form to my eyes. A subtle ground effect via the Alpina-branded front lip, iconic Alpina Classic alloy wheels that hide their mounting hardware and valve caps under the centre cover, and a quad-tipped Akrapovic exhaust balancing out the classic looks in a very contemporary way.
The only element that didn’t unanimously garner praise in the CarAdvice office is the Alpina pinstripe package (which can be deleted), though it helps disguise (or distract from) some of the awkward blown-out detailing of the coupe’s rear flanks.
It’s the Alpina look that really sets the car apart, and arguably becomes the catalyst for buying a B4 S in the first place. Instead of the comparatively in-your-face styling of an M4, the sleek, under-the-radar look and identifiable ‘Alpina-ness’ of the B4 S is a huge part of its appeal.
It points you out as a member of a very exclusive club. BMW M cars, those are common, but Alpina’s sales forecast can be counted on your fingers and toes – like a grey-market rarity, but without the hassle of sourcing, importing and insuring thanks to full-line Australian compliance.
Ardent BMW admirers will find plenty to adore, like CarAdvice contributor James Ward did in 2017, but those without an Alpina adoration will be able to tear the car down on logic against similarly priced competitors. It's no wonder Alpina paints itself as something of an automotive unicorn to give itself some viable market space.
The opportunity to enjoy your Alpina may not come as frequently as its BMW-branded equivalents and their always-ready alertness, but its long-haul composure and subtle, dignified approach to performance are absolutely welcomed in a performance market where every competitor foists track-honed hardware on unsuspecting buyers.
Unfortunately, the ability to uncork that loping long-legged ability becomes rare away from the environment of Germany’s autobahns, which suddenly calls the Alpina B4 S and its value into question. While it may occupy the same pricing space as an M4, the instant urge of BMW’s offering will see it continue to be the favourite for the foreseeable future.