Jaguar XJ vs BMW Alpina B7

What's the difference?

It might be old and facing German competition bursting with advanced technology, but the XJR is still a car you can buy with heart and head. But mostly your heart. It goes like stink, has a much better interior than the Quattroporte and is more interesting than just about anything this big or this grand.

It's also a better car than the Maserati Quattroporte if you want to get on with the driving yourself and is far prettier than the Porsche Panamera. It's a wonderful thing and even more wonderful that Jaguar continues to build it. Long live that supercharged V8 and the XJ is a great home for it.

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.

The XJ has a marvellously exaggerated length, with a rear overhang redolent of Jag's sporting coupe and roadster pair of the time of its launch, the XK. There's nothing else in the segment like it, with the three Germans - Mercedes' S-Class, Audi's A8 and BMW's 7 Series - having gone all Hugo Boss and and in the latter two's case, almost shrinking violet. The only credible Japanese alternative, the Lexus LS, looks like a Lexused 7 Series. The XJR is a more emotional car, like Maserati's Quattroporte.

The R adds an aggro grille, 20-inch wheels with low-ish profile tyres, a bootlid spoiler, red brake calipers and vents in the bonnet. Bits and pieces get the black gloss treatment and there are V8 and R badges, as well as a rather large leaper on the bootlid. Capping it all off are four exhausts poking out from the bumper and distinctive vertical taillights.

Inside remains largely unchanged. The cabin is big and luxurious, leather-lined and very, very comfortable. The front air vents have to be modelled on the de Havilland Comet's integrated jet engine intakes and, again, the dash design stays away from the horizontal lines of its obvious competition.

There is probably a bit much chrome for my liking, particularly on the centre console and around the rotary dial shifter, which reflects sunlight into your face during the day.

The lovely 'Riva Hoop' - a band that sweeps from door to door across the top of the dash - is a great touch and remains a defining feature in the cabin. The last update brought an Audi-like digital dashboard, including maps, but it's not nearly as slick as the German. The graphics for the dials are good (and quick) but the maps are a bit so-so.

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.

It might be over five metres long, but the Jag's cabin isn't as gigantic as that might suggest - luckily, if you want space, the XJ L has it. The SWB version is roomy enough, though, just not palatial. You can fit five people, but the big transmission tunnel will limit the size of that fifth.

Front and rear passengers have a pair of cupholders each, with rubber bubbles to help hold smaller cups in tight. The front and rear doors have pockets but aren't really for bottles.

Boot space is a reasonable 520 litres, with a space saver spare under the floor.

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.

The B7 lists for $389,955, while a 750li is about $319,000. At this level, $70K seems like a downright reasonable premium to pay for a faster, more powerful, better handling and comfier version of the 750Li.

In this case you're paying more but getting more, although standard features are close to identical. There's adaptive LED headlights, head-up display, night vision with pedestrian detection, a 10.25-inch touch screen up front and two screens in the second row for TV and other media functions.

There's a reversing camera, sat nav, harman/kardon surround stereo and Apple CarPlay. There's leather upholstery, seat massagers in the front and rear, four-zone climate control, heated and ventilated front and rear seats, front and rear parking sensors, auto tailgate, sunblinds for the rear and rear-side windows and proximity key.

The safety features are listed in the section below, and that list is also impressive.

Rivals to the B7 include the Mercedes-AMG S63, which lists for $375,000, the $331,700 Audi S8 and even the Bentley Flying Spur, which almost matches its price at $389,500.

Jaguar's lovely 5.0-litre V8 with supercharger continues under the XJ's long and shapely bonnet, delivering a walloping 404kW and a tyre-shredding 680Nm. The sprint to 100km/h for all 1875kg of XJR is completed in an impressive 4.6 seconds, which was very competitive at the car's launch in 2009.

Power reaches the rear wheels via ZF's eight-speed automatic and you can control it with the tacky plastic paddles on the steering wheel. Oh, and it has stop-start.

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 combined cycle figure for the V8 is listed at 11.1L/100km but fully expect to see the 16.1L/100km we got, especially as you try and fail to tyre of the monstrous power delivery and lovely (if muted) V8 roar.

Luckily, even if you're belting it, the 82 litre tank is a generous size and you'll cover a fair amount of ground.

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.

Indecently quick, surprisingly agile and heaps of fun. While the first descriptor applies purely because of its size, the next two shouldn't when you're in command of 5.13 metres of motor vehicle. As with the Audi and now the 7, the Jag has a lot of aluminium to help keep the kilos off and good gracious, it has worked.

The R is based around the short wheelbase version of the XJ for perhaps obvious reasons. Even so, it appears to be the shorter-again XF's because this thing turns in like a demon. No, it won't stay with the dearly-departed XF-R but it does a mighty fine impression of one, just with a better ride quality.

Rear seat passengers should be prepared to feel a lot of wheelslip, especially when in Dynamic mode, as even the fat Pirelli P-Zero's struggle for purchase when the right foot hits the carpet. The V8 rumbles rather than bellows, but the rears cheerfully spin up until the computers and active differential rein things in. Traction control off and you've got a proper tyre-smoker if you're not playing by the rules. Jag's engineers are clearly hooligans at heart.

As always, ZF's eight-speed transmission does an incredible job of marshalling the horses in a rearward direction and when you're not after a bit of sound and light, have achieved a tremendous amount with the damping. When in normal mode, the car glides along, so much so that the lady of the house wasn't so sure it was a sporting sedan.

Once she was apprised of dynamic mode (you have to cycle the button through winter mode first, for some reason), her only complaint was that it was too long and the steering wheel too big for this type of car. I was persuaded of the latter, especially after stepping out of an Audi S3 which has a tiny wheel. Long story short, the XJR is now 'her' car (to be more accurate, the XFR is, but that hasn't arrived yet, so...), as it felt smaller than it was when not parking and she's a sucker for a torquey V8.

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 Alpina B7 comes with all of the BMW 750Li's safety equipment – this includes AEB, lane-keeping assistance and lane-departure warning, blind-spot warning, active cruise control, night vision with object recognition, auto parking and surround view camera.

Along with the suite of airbags, there's traction and stability control and ABS, as you'd expect.

The 750Li and B7 have not been given an ANCAP score.

Jaguar offers a three year/unlimited kilometre warranty and roadside assist for the same period.

Like the F-Type, XJ owners benefit from three years/100,000km free servicing.

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.