UK Drive: Alpina's B4 S combines effortless performance with impressive refinement

What is it?

If you want to buy a fast, sleek two-door coupe, there are a few avenues you could go down. There’s the Audi RS5, with its all-wheel-drive prowess or even the Mercedes-AMG C63 with its powerful V8. Likewise, there’s the BMW M4, with pin-sharp handling and look-at-me styling.

However, there’s another choice – the Alpina B4 S. With a twin-turbocharged 434bhp 3.0-litre engine under the bonnet and a pared-back exterior, it’s an understated way of going very quickly indeed.

What’s new?

What Alpina does is take BMW cars, strip them apart and rebuild them in its own, rather particular way. The beating heart of the B4 S is a BMW-sourced 3.0-litre straight-six, which is twin turbocharged – so there’s a lot of torque to be found as a result.

The dampers have been heftily revised, and a four-outlet Akrapovic exhaust sits at the back to give the car a quality, mechanical sound.

What’s under the bonnet?

As we mentioned, the B4 S utlises a twin-turbocharged 3.0-litre straight-six engine. It produces 434bhp and 600Nm of torque, with power sent to the rear wheels via an eight-speed ZF gearbox. It’s an effortlessly silky powertrain, and torque is available throughout the rev range.

It turns the B4 S into an accomplished cruiser, capable both at accelerating rapidly and also settling down at speed. Speaking of speed, the B4S will crack 60mph in 3.9 seconds – quicker than the BMW M4 can – before hitting a top speed of 190mph.

Economy isn’t bad either, with Alpina claiming that the B4S will return 35.8mpg on a combined cycle and emit 180g/km CO2 – not bad for a close-to-200mph car.

What’s it like to drive?

Somehow Alpina, with every car it makes, manages to combine a well-judged ride with invigorating performance. It’s not often you get both; on many occasions a sports car is too stiffly sprung to enjoy, or isn’t given enough pace to make it exciting. The B4S, however, toes the line between the two.

It gets to the point where you take a look at the large, 20-inch alloy wheels fixed to all four corners and ask ‘how on earth does it ride that well?’. Even larger potholes are brushed aside with little fuss, and yet the Alpina never feels overly soft or wallowy.

Then there’s the performance. Whereas accelerating in the BMW M4 feels razor-sharp and leaves you second-guessing which angle the rear end is about to take, the progressive straight-line performance of the B4 S makes things far more relaxing. There’s plenty of traction for the most part, and all of this adds up to a car in which you feel far happier exploiting on more occasions.

The steering also boasts plenty of heft though limited amounts of feel – both aspects we’d expect of a modern sports car.

How does it look?

Whereas the BMW M4 is all shouty, angular lines and a myriad of air intakes the B4 S is a far more subdued affair. Our test car was finished in, to our eyes at least, a close-to-perfect spec of dark metallic green exterior and tan interior. Alpina vehicles are all about the subtle details, in this case a small front splitter and rear diffuser, along with silver pinstriping along the sides.

One styling aspect which we didn’t completely agree with is the location of the main radar housing at the front of the car. Whereas most vehicles have this placed behind the grille, it’s sat proud of the front splitter in the Alpina – and it looks just a touch clunky.

What’s it like inside?

The B4 S takes all of the best components of a regular BMW and elevates them slightly. Our test car came with optional Merino leather upholstery which commands quite a serious premium at £1,215. Even when fitted with the standard leather the cabin is still very well put together, while the leather-trimmed dash extends the premium feel.

The B4 S is capable of seating four, and though those in the rear have just enough legroom, headroom is quite restricted thanks to the car’s sloping roofline.

What’s the spec like?

There’s a wealth of standard equipment to accompany the Alpina B4 S. Air-conditioning, adaptive sport suspension and the full Akrapovic exhaust system are all included as part of the £63,000 base price.

Our test car, with options such as the previously mentioned Merino leather, came in at £70,045. This price included, interestingly, optional electric mirrors – a £300 option that you wouldn’t expect to pay for with a car in this price bracket.

Verdict

The Alpina B4 S is an accomplished all-rounder offering decent levels of pace without a bone-crushing ride. Yes, it may not be out-there enough for some drivers, but for those who are looking to travel very quickly while attracting little attention, the B4S is hard to beat.

FACTS AT A GLANCE

Model: Alpina B4 S
Price as tested: £70,045
Engine: 3.0-litre biturbo V6
Power (bhp): 434
Torque (Nm): 600Nm
Max speed (mph): 190
0-60mph: 3.9 seconds
MPG (combined): 35.8
Emissions (g/km): 180g/km