BMW Alpina B7 vs Audi S6

What's the difference?

The BMW Alpina B7 is a special car destined (like all Alpinas) to be a collector's item, due to its rarity and exclusivity. I asked Alpina just how many current model B7s there are in Australia and the answer was "less than five", which is just as mysterious as most people find the car in general.

The B7 is fast – too fast to enjoy legally on Australian roads – but it is also supremely comfortable and well appointed. For Alpina fans lucky enough to be driven in on,e this would make for a truly rare and niche way to be chauffeured.

We adore the new S6 sedan. It looks great, feels comfortable and goes like stink all at the same time. What’s not to like?

It also helps that it is relatively good value, safe and practical by large-sedan standards, so it’s a bit of a no-brainer.

But will buyers be quick to dismiss the new S6 sedan because it’s not a more practical SUV? Time will tell, but we hope not.

Does the new Audi S6 sedan represent the best mix of executive style and boy-racer performance? Tell us what you think in the comments below.

This is a good place to start because the B7 looks just like the 750Li it's based on, until you see the first tell-tale signs that it's not one.

There's the front wing with Alpina lettering and the boot-top spoiler, the graphics, which run the length of the car, and the 20-spoke wheels with Alpina badging.

This is late '70s, early '80s styling at its best (and possibly worst), but these special cars can pull off the irony-free look because this is how Alpina BMWs have rolled since 1975, when the E21 320-based Alpina A1/3 was launched.

BMW badges have been left on the bonnet and boot, but there's Alpina B7 BiTurbo lettering in place of the 7 Series identifier.

Most people walked by it in the street thinking it was just a big BMW, others scratched their heads wondering what I'd done to my big German limo and a handful almost dropped to their knees in praise and wonderment at spotting a rare beast like this in the wild.

These people all had their own Alpina stories – one was the third generation of an Alpina-owning family. You become a member a small and passionate club when you buy into this rarefied brand.

The standard B7's cabin is close to identical to the luxurious interior of the 750Li, save for Alpina-embossed stitching in the headrests of the soft, leather seats, the virtual instrument cluster and the Alpina plaque on the centre console denoting the build number.

The B7 is long, low and wide at just under 5.3m end to end, 1.5m tall and 1.9m across. A 3.2m wheelbase means cabin room is more than just spacious.

The B7 rolls off the Dingolfing production line in Germany and is then handed over to Alpina's facility in Buckle, where significant changes take place. Read on to find out how the B7 is different from a regular 750Li.

To these eyes, the new S6 sedan is very attractive, albeit not outlandish, in keeping with its executive focus.

Up front, the subtly aggressive S body kit immediately comes into frame, with the bumper sporting sinister-looking side air intakes.

And, of course, there’s Audi’s signature Singleframe, which is not only large and in charge, but also finished in gloss-black, like many of the S6 sedan’s exterior design elements.

Below the heavily creased bonnet, the HD Matrix LED headlights look both angry and sophisticated, with their integrated LED daytime running lights (DRLs) providing a crisp signature.

Around the side, the S6 sedan goes about its business quietly, but its blistered wheelarches do add some bulk and help to accentuate its strong shoulder line.

And then there are the thick skirts and 21-inch alloy wheels (with a space-saver spare), which have a sporty twin five-spoke design. It’s all very classy.

Speaking of which, the rear end is arguably the S6 sedan’s best angle thanks to its wicked LED tail-lights, which have a segmented signature.

The chunky bumper below incorporates a diffuser element that houses the quad exhaust tailpipes, while a blink-and-you’ll-miss-it bootlid spoiler rounds out the look.

Inside, the S6 sedan is a technological tour de force, with 10.1- and 8.6-inch touchscreens dominating its centre stack. The former is responsible for most of Audi’s latest multimedia system’s functions, while the latter takes care of the climate controls.

This set-up works pretty well, although a few too many taps are required for certain functions, and then there’s the issue of the glass display coverings, which are absolute fingerprint magnets alongside the gloss-black accents used throughout.

That said, the 12.3-inch digital instrument cluster and windshield-projected head-up display on hand are brilliant. In fact, they set the standard for the entire industry thanks to their design and breadth of functionality.

The S6 sedan does, of course, feel a little bit more special than the regular A6 inside, with the obvious additions being the front sports seats, which are covered in supple Valcona leather alongside the armrests. They even have diamond-stitched inserts.

Then there’s the obligatory flat-bottom steering wheel (with paddle-shifters), which is trimmed in Nappa leather alongside the gear selector, upper dashboard, door shoulders and knee rests. Indeed, hard plastics are hard to find here.

Meanwhile, a black headliner adds to the sportiness alongside the black Alcantara door inserts, but the cabin is otherwise a familiar (read: classy) affair.

The B7 is a five-seater limousine although with the fold-down rear centre armrest which houses the media control panel the back is really set up to carry two.

That 3.2m wheelbase means cabin space is enormous. At 191cm tall I can sit behind my driving position with about 30cm between my knees and the seatback. Those rear doors open wide and the entrance is huge, making entry and exit almost as easy as just walking through a doorway. The air suspension also rises and lowers the B7's ride height for better access.

Storage is excellent, with two cupholders and door pockets for rear passengers, along with the area inside the centre armrest.

Up front, the driver and co-pilot have a deep centre console storage bin with split-opening lid, two cupholders and door pockets.

Luggage space is good, with a 515-litre boot.

Measuring 4954mm long, 1886mm wide and 1446mm tall, the new S6 sedan is a large sedan in every sense of the term, which is mostly good news when it comes to practicality.

Cargo capacity is decent, at 520L, but can be increased to an undisclosed amount with the 40/20/40 split-fold rear bench stowed.

Speaking of the boot, there are four tie-down points and a cargo net to help secure loose loads, while a bag hook and a side storage net are also on hand, alongside a 12V power outlet. Bulkier items will, however, be confronted by a decent load lip.

In-cabin storage options are numerous, but not all are effective. The glovebox is well-sized, while the driver-side cubby is surprisingly large, but the central bin is shallow, mostly taken up by the wireless smartphone charger, two USB-A ports and the SD and SIM card readers.

A pair of cupholders is located in the centre console, with a 12V power outlet found in between, while the front door bins can accommodate one regular bottle each, just like their rear counterparts.

In the second row, there’s a fold-down armrest with two more cupholders as well as a shallow storage tray, while cargo nets are affixed to the front seat backrests.

The rear bench is pretty comfortable, with four inches of legroom available behind my 184cm driving position alongside decent toe-room. Headroom is also good, with about two inches on offer.

That said, three adults sitting abreast won’t enjoy the experience, due to the large transmission tunnel, which makes for limited footwell space. At least they’ll have access to a couple of USB-A ports and a 12V power outlet, below the central air vents.

For reference, child seats can be fitted to the outboard seats via top-tether and ISOFIX anchorage points.

The new S6 large sedan is priced from $149,900 plus on-road costs and is far better value than before, even if it does command a $33,900 premium over the regular A6's flagship variant.

Compared to its predecessor, the new S6 sedan is $21,480 cheaper, while Audi Australia claims it has also added $20,000 worth of kit.

Standard equipment not already mentioned includes metallic paintwork (our test vehicle was finished in Tango Red), dusk-sensing lights, rain-sensing windshield wipers, soft-close doors, auto-folding side mirrors with heating, rear privacy glass and a hands-free power-operated bootlid.

Inside, satellite navigation with live traffic, Android Auto and wireless Apple CarPlay support, digital radio, a 705W Bang & Olufsen 3D sound system with 16 speakers, a panoramic sunroof, keyless entry and start, power-adjustable front seats with heating, a power-adjustable steering column, four-zone climate control, an auto-dimming rearview mirror and LED ambient lighting feature.

Of note, buyers can opt for the $7700 Dynamic Package that bundles in speed-sensitive electric power steering, a rear limited-slip differential and all-wheel steering. It was not fitted to our test vehicle.

In terms of rivals, the BMW M550i sedan is identically priced, while the Mercedes-AMG E53 sedan is much more expensive, at $173,800. The S6 sedan arguably has the former beat on value but loses the performance battle due to its 390kW/750Nm 4.4-litre twin-turbo V8.

Alpina takes the 4.4-litre twin turbo V8 from the BMW 750Li and rebuilds the engine by hand. Alpina fits its own turbochargers, air-intake set -up, high-capacity cooling system and Akrapovic quad exhaust. Output is 447kW and 800Nm – an increase of a whopping 117kW and 150Nm over the 750Li's grunt.

It's interesting to note that the V12-powered 760Li has a smidge more power, at 448kW, and the same torque output as the B7.

How fast is the B7? Supercar fast – the B7 has a top speed of 330km/h, which will see it outrun a McLaren 570 and almost keep up with a Ferrari F12. That's quite incredible for a 2.3-tonne limousine with three TVs on board. A 0-100km/h time of 4.2 seconds is also hugely impressive.

In comparison, a 750Li has a 0-100km/h time of a not-too-shabby 4.7 seconds, but the car is electronically limited to 250km/h.

An eight-speed automatic transmission shifts gears smoothly, although a little slowly in Normal mode, while Sport and Sport+ add urgency and harder shifts.

Finally, the B7 is all-wheel drive, and those rear wheels are designed to steer slightly for better cornering performance.

The new S6 sedan is powered by a hard-hitting 2.9-litre twin-turbo V6 petrol engine that produces a strong 331kW of power from 5700-6700rpm and a punchy 600Nm of torque from 1900-5000rpm.

Compared to its aforementioned predecessor, power is unchanged, while torque has increased by 50Nm.

This unit is mated to a 48V mild-hybrid system that includes a trick Electric-Powered Compressor (EPC), which helps to reduce its turbo lag.

A reliable eight-speed torque-converter automatic transmission is responsible for swapping gears, while drive is sent to all four wheels via Audi’s rear-biased quattro system.

This combination helps it sprint from a standstill to 100km/h in an impressive 4.5 seconds, while its top speed is electronically limited to 250km/h.

The B7 is probably not the car to own if you're concerned about either fuel prices or emissions, but then the twin-turbo V8 may not be as thirsty as you'd think, with Alpina stating that, after a combination of urban and open-road driving, you should only use 9.6L/100km.

My time in the B7 saw me double that usage but this could have had something to do with me turning off the stop-start system and driving in Sport mode constantly.

The new S6 sedan’s fuel consumption on the combined-cycle test (ADR 81/02) is 8.4 litres per 100 kilometres, while claimed carbon dioxide emissions are 197 grams per kilometre. Both figures are pretty keen given the level of performance on offer.

Audi says the aforementioned 48V mild-hybrid system reduces fuel consumption by 0.4L/100km thanks to its coasting ability, which sees the engine turn off for up to 40 seconds between 55km/h and 160km/h. It also engages idle-stop from 22km/h.

In our real-world testing, we averaged 14.4L/100km over 100km of driving skewed towards country roads over city traffic, with limited highway time. It’s worth noting that my spirited driving inflated this result. That said, while its fuel consumption is not as bad as it appears, this is still a thirsty sedan.

For reference, the S6 sedan’s 73L fuel tank takes 98RON petrol at minimum.

Who on Earth thinks a BMW 750Li isn't fast enough or comfortable enough, even with all its horsepower, luxurious cabin and technology? Alpina, that's who.

Redevelopment of the 4.4-litre V8 with new turbochargers, a high-capacity cooling system, different air suspension set-up and an exhaust system made by Akrapovic have made this already exceptional car better. Better to drive and better to be driven in.

The ride, even on those 21-inch wheels and low-profile Michelin Pilot Super Sport tyres (255/35 ZR21 on the front and 295/30 ZR 21 on the rear) is incredibly comfortable. I drove it and also had a chance to recline in the back and be chauffeured (by our photographer) and the ride was so composed and refined it was hard to believe I was travelling along some truly awful urban roads with their cracked and pot-holed surfaces.

And it's quiet, too. Which will suit those in the back being transported swiftly from the airport to their next meeting, but if you're after a loud and angry exhaust note then you won't find it in the B7. Sure, from the outside at full throttle the B7 has a menacing growl, but this isn't a BMW M car that will bark and snarl. 
See, while BMW's M division makes brutal, loud, high-performance versions of their regular cars, Alpina makes comfortable, stealthy, high-performance ones.

All-wheel drive provides fantastic traction and ensures that grunt doesn't just tear the tyres off those rims when you sneeze on the throttle.

And while the air-suspension is soft and comfortable, adaptive dampers adjust for when the road goes twisty, providing impressive handling for a heavy and long car.

Really, though, the B7 is built for long, endless stretches of roads, and the acceleration beyond 100km/h is almost as startling as that from 0-100km/h, as it wants to push straight past 200km/h towards that 330km/h top speed.

Which, unless you know a good lawyer or happen to be one, will send you straight to jail. Yes, the B7 is probably too much car for Australian roads. Only on a German autobahn would a B7 be fully at home.

I felt like I was given a Melbourne Cup-winning racehorse for a week but could only ride it in my suburban backyard.

The S6 sedan has no right being this good in a straight line and around corners…

Much of its success is owed to the 2.9-litre twin-turbo V6, which is now one of my favourite engines being built today. Simply put, it absolutely hammers.

Punch the accelerator from a standing start and it doesn’t take long for 600Nm to be on tap all the way through, and just a little bit beyond, the mid-range.

Occupants are firmly pressed into their seats as the S6 sedan sprints towards the horizon with vigour. Soon enough, 331kW arrives and hangs around until just prior to the redline.

Needless to say, this acceleration is addictive, and the EPC deserves some of the credit, as it effectively mitigates any dreaded turbo lag and ensures the engine is always seemingly on boost.

But we also need to acknowledge the eight-speed torque-converter automatic, which is a real beauty. Gear changes are nice and smooth, which is great, but what’s even better is their relative quickness – dual-clutch transmissions be damned!

Of course, extra performance can be extracted by switching between the engine and transmissions’ settings but, rest assured, they both stand up, no matter what.

However, we’d suggest spending time in the former’s most aggressive setting, as it unleashes the sports exhaust system, which sounds unreal.

Upshift with intent and you’re met with a booming ‘brap’. Downshifts and the overrun will even gift you a series of pops. In fact, the S6 sedan soundtrack sounds strangely similar to that of the five-cylinder RS3, and we have absolutely no problem with that.

Better yet, the S6 sedan has an appetite for corners, with its neutral handling a standout, partly thanks to its hard-working rear-biased quattro all-wheel-drive system, which works in tandem with all the other electronics to ensure there is plenty of grip at any given time.

This controlled driving pleasure is enhanced by the electric power steering on hand, which has a variable ratio. At low speed, it’s nice and light, but those after more heft can always switch to another one of its settings, which become progressively heavier… arguably too heavy.

Feedback through the wheel is also good, while the steering itself is pretty direct, lending itself to sporty driving, which, of course, is half of the S6 sedan’s mantra.

Coming into corners, braking performance is solid, thanks to the massive 400mm front and 350mm rear discs with red callipers, so the driver is brimming with confidence at every turn, even though there’s an unladen weight (with 75kg driver and luggage) of 1985kg to manage.

But let’s not forget the S6 is an executive sedan, so it has to ride like one. Thankfully, it does. The independent five-link suspension has air springs and adaptive dampers, which serve up comfort in spades, especially at high speed.

Its firm tune does come into frame when travelling on unsealed or uneven roads, with this exacerbated by the large 21-inch alloy wheels, which have a penchant for catching sharp edges.

ANCAP awarded the A6 range (including S6) a maximum five-star safety rating in 2018.

Advanced driver-assist systems extend to autonomous emergency braking with pedestrian detection, lane-keep and steering assist, blind-spot monitoring, rear cross-traffic alert, adaptive cruise control with stop-and-go functionality, high-beam assist, driver attention alert, hill-start assist, tyre pressure monitoring, surround-view cameras and front and rear parking sensors. Yep, buyers aren’t left wanting here.

Other standard safety equipment includes six airbags (dual front, side and curtain), electronic stability and traction control systems, anti-skid brakes (ABS), brake assist and electronic brake-force distribution, among others.

The B7 is covered by BMW's three-year, unlimited-kilometre warranty. Servicing is recommended every 12 months or 15,000km. The B7 is covered by BMW special vehicles servicing plan, which means services are cost-free for the first three years of the car's life.

The S6 sedan comes with Audi Australia’s three-year/unlimited-kilometre warranty, which falls short of the premium market’s relatively new five-year standard that was set by Genesis and followed by Mercedes-Benz.

Three years of roadside assistance is also bundled in, although this term can be extended up to nine years if the vehicle is serviced at an authorised dealership, which is great.

Speaking of which, service intervals are every 12 months or 15,000km, whichever comes first. Capped-price servicing plans are available, costing $2350 for three years/45,000km or $4110 for five years/75,000km. They’re pricey, but you weren’t expecting the opposite.