Alpina B4 Gran Coupé 2023 review

Refinement is exquisite; the cabin is a leather-lined capsule, beautifully cocooned from the outside world. The steering is measured in feel, meaty in weight. Green and blue stitching. Blue dials. It’s definitely an Alpina.

Maybe one of the last new Alpinas as we know them. When the Buchloe-based marque’s longstanding cooperation agreement with BMW ends in 2025, it will become part of the BMW Group and the type of new cars it will produce from that point onwards is still TBC: perhaps ultra-high-end, BMW Alpina-badged derivatives positioned above the 7- and 8-series; perhaps something different.

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Either way, this is an Alpina in the finest tradition: a high-performance combustion-engined model that is pre-assembled on a BMW line then finished in-house at Alpina’s Buchloe base. Alpina makes its own engineering alterations to the powertrain, drivetrain, suspension, brake system, body and beyond, and its leather shop gets to work on the interior.

Source material is the BMW 4-series Gran Coupé, the large-booted, five-door derivative of the 4-series, which also shares its body with the i4. BMW doesn’t make an M4 Gran Coupé (the M440i is as spicy as the 4GC gets) so this car, powered by an Alpina-altered version of the M3/M4’s potent S58 engine, exists in its own niche. 

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It’s also a new one for the B4 line, as the previous generation was a two-door coupe. The Gran Coupé costume resembles a saloon more than a coupe to my eyes, although it feels like a coupe to my scalp when sitting in the back; I’m 5ft 11in and the top of my head brushes the roof and my temple the cant rail if I sit back, but there’s plenty of leg room. The controversial twin-tombstone grille’s chrome edges match the big, chrome-edged Alpina Classic wheels but don’t play quite as well with the hallmark Alpina script along the chin spoiler beneath, better suited to more traditional, square-jawed models.

The 3-litre straight-six’s twin turbochargers are re-engineered by Alpina with smaller housings, prioritising throttle response and driveability over ultimate power: the B4 Gran Coupé develops 488bhp to the M3/M4 Competition’s 503bhp, but a gargantuan 538lb ft to its 479lb ft, spread like butter between 2500 and 4000rpm. Alpina’s reasoning is that it makes the B4 as quick, if not quicker, in most real-world scenarios, and the B4 does feel enormously fast. The big swell of torque is almost EV-like, in that there’s such a deep well of acceleration to draw from at any time. 

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That said, it’s not an entirely instantaneous hit: despite the swifter turbo response there is still lag, and even in manual mode – via lovely aluminium shift paddles added by Alpina – there’s a softened edge to the initial hit of acceleration. It feels like it might be a deliberate micro-delay, programmed into the throttle response to prevent the mighty slug of torque from feeling jerky or uncouth. It punches hard, but it’s wearing padded gloves.

In default Comfort mode, the six sounds both muted and gruff rather than sonorous. Noise is nicely suppressed; uncorked a little in Sport, it gains a rasping, though still subtle, edge and an occasional arsenal of pops and bangs on the overrun from the Alpina-specific exhaust system. This being an Alpina, there’s an additional Comfort Plus setting for a softer-still ride from the adaptive dampers, which have Alpina-specific tuning and work in combination with new anti-roll bars and extra negative camber at the front.

The ride is firmed up a little in this particular car due to Alpina’s decree that the rear tyres (bespoke Pirelli P Zeros, with ALP markings on the sidewalls marking them out as being created specifically for the car) be inflated to 3.5bar to be able to sustain regular top-speed runs on the autobahn (no 155mph limiter here; the B4 runs unfettered to 187mph). That, together with the 20-inch wheels, sharpens the ride’s edge on British B-roads, although overall body control and the way the car absorbs big bumps is lovely. It handles its 1.9-ton mass well, only becoming wallowy when pressing on in the loosest-limbed Comfort Plus setting. 

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Big tyres mean a big contact patch, and both lateral grip and traction are humongous, even with all the electronic systems turned off. The all-wheel-drive system’s torque split is biased far more to the rear than in the regular 4-series, although you can’t make the car rear-wheel drive only as per an M model. 

Under heavy braking is where the B4 GC’s considerable mass makes itself felt on the road, though it stops very well for a car of this bulk. This particular example is fitted with the optional £1770 High Performance brake system, with different pads and extra ventilation. Pedal response is irritatingly grabby around town but less of an issue at higher speeds.

The B4 Gran Coupé’s sophisticated refinement is a double-edged sword: as a driver’s car there’s a layer of insulation that comes between you and the last degrees of tactility that would make it truly involving to drive. But that also makes it easier to live with than an M car, a beautifully rounded proposition and in keeping with the old-money character of a true-blue Alpina.

BMW Alpina B4 Gran Coupé specs

This story was first featured in evo issue 311.