Overall rating: 5/5

Aside from looks that can be a touch bulky in long-wheelbase format and a bit of wind noise from its stylised door mirrors, there's little to fault with BMW's sixth-generation 7 Series and a lot to enthusiastically praise. A cabin of sublime quality, a flawless ride and immense levels of refinement are all topped off with some dynamic flair and an equipment list that reads like a Tolstoy epic. Stick with the regular wheelbase, rear-wheel drive diesel model as reviewed here and you will be in possession of one of the finest three-box saloons on the planet.

In the metal 4/5

The latest BMW 7 Series takes the fifth-generation's look and makes it a bit sleeker. It's therefore familiar and also fresh at the same time, although whether it could be called pretty - or even handsome - is another matter. Some will like the wider front light clusters, absolutely gigantic kidney grilles (good luck enlarging those at mid-cycle facelift time, BMW), the side profile that lacks a lot of fussy design detail and the rear, which incorporates a wide bar of chrome; others will think it a little ungainly, even more so in the long-wheelbase versions (badged Li, Ld or Le depending on what's under the bonnet) that add 140mm to the 7 Series' midriff. We happen to quite like the exterior, although BMW only offers it in a traditionally staid array of colours - mainly greys and silvers - that don't enliven the aesthetic much.

If the exterior has the potential to be divisive, the interior should float any captain of industry's boat. It is magnificent. Beyond reproach. There's not a single centimetre of black plastic on display anywhere and everything you lay hands on feels of the utmost quality. The seats are comfortable, the widest variety of driving positions imaginable should be attainable and there's an acre of room in even the standard, 5,098mm-long 7 Series. Go for the long wheelbase and any giant going could sit in the back.

Not only is it built fabulously but it's also stocked up to the gunwales with technology. Standard equipment incorporates the expected, like cruise control, leather, climate control, head-up display and a wealth of comforts (including air suspension with Dynamic Damper Control on all models), but get busy with the options list and there's little short of air-to-air missiles that can be loaded into the Seven. Laser headlights, semi-autonomous driving capability, Remote Control Parking (yes, it means exactly what it says - you can park the car without being in it), twin sunroofs with LEDs in them for mood lighting (called Sky Lounge Panoramic Glass Sunroof), massaging, electrically adjustable, heated and cooled rear seats and a tablet in the rear armrest console to control all the infotainment are just some of the technical highlights. With gesture control, the car even knows what you're doing when you're waving your hands about in the air... no, we don't mean in THAT way, thank you.

Driving it 5/5

This 3.0-litre turbodiesel engine is the tried and trusted single turbo unit that seems to have been in service for aeons. Don't let that put you off, though, as it's a thoroughly competent and up-to-date iteration of the inline-six. Mild increases over the old model see peak power and torque standing at 265hp and 620Nm respectively. And as the 7 Series has been on a diet, thanks to Carbon Core lightweight build techniques learned from the BMW i3 and i8 shaving up to 130kg from its mass, it is relatively lean in this class. The longer wheelbase adds 45kg to proceedings and xDrive all-wheel drive another 70kg, but this 'regular' 730d clocks in at just 1,755kg in total.

That means the 730d is plenty quick enough in a straight line, while through the curves it is agile and feels sporty, like a proper BMW should. There's a slight hindrance to spirited cornering in the form of steering that in light and lacking feedback, even if you knock the Drive Performance Control switch to Sport. Yet the rack is at least direct and consistent in terms of input and response, which allows you to lean on a chassis possessed of rare talent. Grip levels are high and the Dynamic Damper Control-equipped air suspension keeps the limo's frame in check. So while it may be nearly 200hp down on the 750i, its mere 30Nm deficit to the same model means the 730d feels pacey when on a charge - and it possesses excellent brakes, too, with lovely pedal modulation.

But enough of the tomfoolery. Executives, embassy diplomats, oil industry barons and sheikhs the world over don't buy these big barges for their ability to tear up a mountain road. So when the going becomes calmer, can the Beemer hold a candle to the Mercedes-Benz S-Class, for decades the leader in this field? Oh, yes. Yes, it can. If there is one criticism of the Seven's off-the-boil demeanour, it's very mild wind buffeting from its unusual door mirror supports; look closely and you'll see they're mounted on a blade that extrudes from the window trim surround itself, rather than the more traditional locations of in the 'mirror triangle' at the base of the A-pillar or on the doors themselves. A pity, as this minor audible indiscretion is only the second black mark on the BMW's dynamic copybook after the steering.

And one final gripe before the eulogy begins - we saw 33.2mpg (8.5 litres/100km) during a route that had some motorways included with a bit of careering around Portuguese mountains; even allowing for the inappropriate hill climbing, that's still some way off the official 62.8mpg. Instant economy read-outs while holding a steady 120km/h suggested it was sipping diesel at around 4.0 litres/100km, so maybe the official consumption won't be so far-fetched for core 7 Series customers. Usefully, the distance to empty display is not hidden in the scrolling menu of the trip computer but is permanently displayed in the corner of the fuel gauge. Starting with a full tank, our 730d never showed anything less than 800km of range, even after that 'challenging' 200km test route.

So aside from a minor bit of wind noise, it is a faultless cruiser; utterly, utterly faultless. The ride is absolutely sublime, eradicating the passage of surface bumps and ripples into the cabin so well that you begin to wonder if every road you're driving on has been re-laid in fresh tarmac within the past few days. The six-cylinder diesel dies away to the faintest, muscular murmur and tyre noise is... well, we have no idea what it is. We never heard a peep out of the rubber. Good luck also in trying to detect the eight-speed Steptronic automatic doing anything at all, save for hurling power at the rear wheels. This transmission is fluidity in engineering form. The net result is that we drove this car in Portugal and if BMW had told us to take it back to Munich, non-stop, we wouldn't have hesitated for a second. In fact, we'd have probably then driven it back to Porto again.

What you get for your money 5/5

It might seem odd to give an expensive luxury car full marks here, but at a starting price of €96,880 for the BMW 730d it's only a modest increase in cost over the outgoing 7 Series, for a lighter, more economical vehicle that has all the luxuriousness of the much more expensive Bentley Flying Spur and which will be dripping in commodities. That you could tax this all-singing, all-dancing limousine for a piffling €200 a year is simply the glacé  cherry on a very sweet cake.

Alternatives

Audi A8: mildly refreshed and while the styling is less distinctive and adventurous than that of the BMW, it's likely to offend fewer people to boot. Staid chassis, due for replacement in a few years - wait for that example instead.

Jaguar XJ: if the Audi is safe, this is stylistically the polar opposite. Like the 7 Series, also has a gorgeous cabin but it too has been around for a while now. The BMW is quantifiably the better car.

Mercedes-Benz S-Class: for some, this is 'The Best Car in the World' and we reckon the 7 Series has its measure. These two tech-toting Germans rule this class at the moment.

Summary

It's dynamic. It's comfortable. It has a ride second to none. It can be equipped with every toy you could imagine. It has a range of excellent drivetrains. And it won't cost the Earth to buy or run. OK, the steering is a little numb and the mirrors make some noise and it's more likely you'll see 40-50mpg in reality... yet aside from these foibles, this is a crushing display of brilliance from the new BMW 7 Series. In our opinion, it's the outright class leader. Sensational stuff from Munich.