Written by Alan Taylor-Jones Updated: 2 September 2023

Overview

While everyone knows a proper M-badged BMW is a bit of a weapon (or possibly driven by one), there is a more discreet option available. That’s where the BMW-Alpina B4 Gran Coupe and its rangemates come in, offering almost as much performance as an M car without shouting quite so loudly.

Besides, while you can’t get a BMW M4 Gran Coupe, you can buy a four-door coupe version of the B4 along with a saloon and Touring-badged estate. All are powered by a 3.0-litre twin turbo straight-six that isn’t as powerful as the one in the M3 and M4 but produces more torque, while four-wheel drive is standard.

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As is tradition with Alpina, you get distinctive alloy wheels and unique styling touches to mark it out from lesser BMWs including bumpers and a different exhaust system. You can even get a stripe package in a variety of colours that you’ll either love or hate.

We’d argue the car that’s the B4 Gran Coupe’s closest competitor is the Audi RS5 Sportback, although you might also consider the RS4 Avant, BMW’s own M3 and M4, or even the i4 M50. Mercedes fans might also consider the AMG CLA 45 and C63.

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What’s it like inside?

There are a few reminders that this is no ordinary 4 Series inside. You’ll find a numbered plaque next to the handbrake switch, an Alpina badge in the middle of the steering wheel that’s wrapped in suppler leather and Alpina branded displays on the digital instruments.

There’s the option of a few interior trims and also upgraded leather trim in a choice of colours. It’s an expensive option but one that lifts the interior over the 4 Series on which it’s based. That’s because, funnily enough, most of the interior is exactly the same as you’d find in a regular Gran Coupe.

That also means infotainment, space and practicality is exactly the same, so if you want to know more about that and the rest of the interior, we’d advise hopping over to our main BMW 4 Series Gran Coupe review.

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Comfort

Standard BMW leather seats can be a little bit firm, so although the optional Lavalina leather is a pricey upgrade, they are more supple. Given its use elsewhere in the cabin, it also helps lift the interior over a regular 4 Series. Front electric seat adjustment and heating is standard, although it’s disappointing that adjustable lumbar support is an optional extra for driver and passenger.

For the most part it’s exactly the same as any other 4 Series Gran Coupe, with a good driving position that helps long distance comfort and front seats that are far less impractical than the buckets available in the M3 and M4.

Safety

Since the BMW 4 Series Gran Coupe and therefore the B4 shares so much with the 3 Series, that car’s five-star Euro NCAP crash test rating applies. The saloon was tested by the safety body in 2019, and it earned high percentage ratings across the board.

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There are seven airbags (including a driver’s knee bag) fitted, plus Isofix child seat attachments in the back. While the extra back doors improve access to the rear seats when compared with the coupe, their narrow openings mean it’ll still be a bit of a struggle to get a bulky child seat in.

A system called Active Guard Plus is fitted as standard on the Gran Coupe. Among its suite of safety features is front collision warning with brake intervention and pedestrian detection (a form of autonomous emergency braking or AEB), plus lane-departure warning.

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What’s it like to drive?

With 495hp and four-wheel drive, 0-62mph takes a mere 3.7 seconds as the eight-speed automatic gearbox fires through the gears. There’s great traction off the line and the B4 makes light work of any overtaking opportunity, it’s properly fast. It can be a little slow to kick down in Comfort mode, but the sportier settings sharpen things up. A more immediate response can be had from the tactile metal gearshift paddles behind the steering wheel, although an M4’s ‘box is sharper still.

That is the point of the B4 though, offering near M4 levels of performance with a greater everyday liveability. For instance, Alpina’s sports exhaust plays more muted music than the M car’s rowdier pipes, and you don’t get its wider wheelarches either. The suspension is also a little softer, delivering an impressive blend of impact absorption and body control. You’re certainly aware of the road’s surface, but it’s less bothersome than some M Sport versions of regular BMWs and preferable to the Audi RS5 Sportback.

The B4’s handling is also preferable to its four-ringed foe. Despite weighing very nearly two tonnes it’s more than happy to be hustled along, the Alpina specific tyres delivering terrific grip while the body stays impressively level during hard cornering. Steering weight is heavy enough to be reassuring without being unnecessarily so, racier modes bringing greater resistance if you wish, with a well-judged rate of response. It makes guiding the B4 along a pleasurable experience whether you’re commuting gently or going for a blast at the weekend.

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A distinctly rearward bias to the four-wheel drive system makes it feel livelier than the RS5, especially with the stability control in a more relaxed state or off. If you do decide to have a little sideways fun, the four-wheel drive system is always on hand to make sure things don’t get too lairy. When you’re done with driving quickly, the engine fades into the background, gearchanges are smooth, wind noise is well contained and the B4 once again becomes a perfectly civilised car.

Ownership costs and maintenance

Despite being a subtler choice than the M3 and M4, it’s every bit as expensive even before you’ve raided the options list. You can buy an RS5 for less, though. Of course, the costs don’t stop there with a fairly ferocious thirst if you start exploring the performance. Miles per gallon hovered around the mid-20 mark and it wasn’t at all hard to get it into the teens.

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What models and trims are available?

There’s only one trim level as such, with a range of options to tailor the car to your liking. As standard you get three-zone climate control, adaptive dampers, LED headlights, electrically adjustable heated seats up front with driver’s memory, a heated steering wheel, sat nav and smartphone mirroring.

What else should I know?

Despite being bought by BMW in 2022, Alpina isn’t suddenly going to start making thousands of B4s or any other of existing models. This exclusivity is part of the charm, although far fewer people are going to clock you’ve spent over £80k on a car than if you’d bought an M3 or M4.

To see whether we recommend the B4 Gran Coupe and what ratings we give it, head to the verdict page.