BMW Alpina B5 review

We can only imagine that some high-ups at Alpina know where the bodies are buried at BMW. Okay, that might sound a bit far-fetched, but how else do you explain the long-standing and happy partnership between one of the world’s industrial leviathans and a pint-sized outfit like Alpina?

It’s a relationship so entwined that Alpina is allowed to infiltrate BMW’s production process and spirit away all of the constituent parts required to build a whole range of cars. What’s more, these are cars that provide direct competition to BMW’s top-end performance variants.

Take the Alpina B5 saloon. Sure, Alpina will gladly rob sales from super-saloons such as the Mercedes-AMG E63 and hot versions of the Porsche Panamera, but that also means the B5 is a bang-to-rights rival to the current BMW M5 – and, to within a couple of thousand quid, it’s priced accordingly.

Yes, the M5’s Botoxed bumpers and chiselled mirror housings give the car a more ripped appearance than Alpina’s more conservative rendition of the 5 Series saloon, but the B5 is not without its own embellishments, including optional slender pin-stripe decals, Alpina emblems and those iconic sundial alloy wheels.

There’s also a fair bit of mechanical symbiosis going on. Both cars employ twin-turbocharged V8 engines and both use four-wheel steering and traction-enhancing four-wheel drive, along with mind-boggling terabytes of electronic intervention systems, in an effort to maximise power delivery and enhance cornering stability.

This can only be a good thing, given the lurid performance – the B5 will thunder to 62mph 3.5sec and will best 200mph, making it faster than the M5.

Read on to find out if the B5 is worth choosing over its BMW cousin and, indeed, other super-saloons.

Despite its philanthropy, BMW has resisted the temptation to hand over all the crown jewels. The B5 and M5 may both be powered by 4.4-litre V8s, but the latter’s highly specialised power unit is a jealously guarded device, so the B5 has to make do with an engine that’s also found in more run-of-the-mill 5 and 7 Series models. Not that this has prevented Alpina from getting this relatively humble V8 to conjure up a cauldron full of seriously explosive performance.

Chief among Alpina’s efforts is a pair of pressure-cooker turbochargers that ramp up the power in the V8 from a not inconsiderable 444bhp in the engine’s more usual applications to a cork-popping 600bhp. Obviously, increases on that scale necessitate myriad engine and gearbox reinforcements, along with considerable cooling upgrades; you only need to listen to the B5’s whirring fans inhaling enough air to cool the Palm House at Kew Gardens to appreciate the direct correlation between its immense power output and the amount of heat its mighty engine generates.

Judged next to M5’s revvy freedom and near-instantaneous accelerator responses, though, the B5’s engine can seem a tad tardy. Yet it’s merely the power delivery that’s lacking compared with the M5 because, once you’ve got past the delay while the turbos wake up, you’ll not feel short-changed by the B5’s performance; if you do, it’s probably time to seek medical assistance.

Getting the B5’s chassis to cope with this level of performance is no mean feat, either. To this end, Alpina has fitted its own suspension components and tuned the steering – which, as we’ve already mentioned, works at both ends of the car. The steering wheel’s weighting is consistent and nicely judged, offering enough resistance without being overbearing and providing a pretty steely connection to the front wheels.

The B5 is also far more relaxed at lower speeds than the M5. Then again, being escorted off the premises jammed between a couple of burly bouncers is preferable to the pillar-to-post shimmying generated by the M5 over bumpy roads at lower speeds. Once the action hots up, however, the roles are reversed. While the M5 sparkles and elevates its suppleness and poise to a level that few – if any – super-saloons can match, the B5 begins to feel less able to control its mass and suffers from levels of road impact that you’re never exposed to in the M5. Perhaps more surprisingly, given the B5 is alleged to be the more refined car, it generates more tyre and wind roar at motorway speeds than the supremely refined M5.

Other than the bespoke blue speedo and rev counter displays, which look rather blurred compared with BMW’s super-sharp graphics, along with the Alpina-embossed threshold kick plates that greet you when you open the doors, there are very few differences between the B5 and any high-end 5 Series. Material quality and the overall fit and finish are first class and you get well-bolstered, supportive sports seats that offer a wide range of electric adjustments.

However, unless you specify the pricey Alpina-specific leather upgrade, the B5 doesn’t feel as plush as the upgraded interior that’s standard in the M5, nor do you get that car’s bespoke sports seats that offer even greater support. That said, despite the pedals being slightly offset to the right, you shouldn’t have too many problems finding a decent driving position. Visibility is pretty good all-around; there are front and rear sensors, plus a rear-view camera, to help guide you into tight parking spaces.

The B5 also comes with BMW’s famed iDrive, which is one of the most intuitive infotainment systems of all to use while driving. This is down to better organised menus than those in the Mercedes-AMG E63’s infotainment system and the fact that everything can be accessed promptly through the high-definition touchscreen, the excellent rotary controller with shortcut buttons or the handwriting facility. The additional gesture control system is a bit of a gimmick, though, and doesn’t add to the system’s ease of use.

In the front, there’s exactly the same amount of space as there is in any ordinary 5 Series, meaning plenty of head and leg room, plus a generously wide interior.

There’s enough space for two tall adults in the rear, too, but carrying a third isn’t a comfortable experience on long journeys; shoulder room is tight and the middle occupant has to straddle a raised central tunnel. There’s actually more leg room in the Mercedes-AMG E63, although the margins are small, while the B5 beats it for head room by a whisker.

As for the boot, there’s enough space for a couple of large suitcases and some smaller bags. However, rather than being a square shape, the load bay is full of contours that can be restrictive when trying to load large, bulky objects, while the E63’s boot is that bit larger. That said, like the E63, for those requiring more luggage space the B5 is also available as an estate (known as B5 Touring). The M5 comes only as a saloon.

The B5 is no more expensive to run than your average family hatchback. Yeah, right!

For a start, its asking price falls only slightly south of six figures, and that V8 engine won’t be easy on tyres or fuel costs. Moreover, official fuel economy of just 26.9mpg is the stuff of fantasy, because if you use the engine as it’s intended you’ll be lucky to see half that figure. You’ll also spend plenty of time with a green nozzle in your hands, since the tank is no bigger than that in a standard 5 Series at 66 litres.

You’ll need huge reserves of cash to run a B5 as a company car, too. The whopping list price and CO2 emissions of 240g/km place the car in the top 37% band, meaning benefit-in-kind payments will be nothing short of astronomical. That said, the same issue faces buyers considering a BMW M5 or Mercedes-AMG E63.

If you want to maximise the performance aspects of your B5, then you can specify a handling-enhancing slip differential and more powerful brakes, although you’ll get very little change out of £4,000 for those. The cost of the differential is made all the harder to swallow when you consider that most of the B5’s rivals come with this feature as standard.

Although the B5 hasn’t been crash tested by Euro NCAP, the regular 5 Series gained a five-star rating, with a particularly high score for adult occupant protection, so you can feel pretty confident that you’ll be well protected should things go pear-shaped.

For all the latest reviews, advice and new car deals, sign up to the What Car? newsletter here