SINGAPORE – One of the basic rules of motoring is that the amount of driving pleasure in a car is inversely proportional to the number of seats it has. Formula One car: one seat, total driving nirvana. Volkswagen Sharan: seven seats, woof woof to drive.

Another of the car world’s inviolate rules is: the less your wife approves of a car, the more fun it is. When did I meet your wife, you must be wondering? I haven’t. I swear I’ve never touched her. I just know that women are practical, and think boot space is more important than horsepower. And they’re territorial, which is why they tend to resist your purchase of anything remotely sexy and magnetic, like any two-door Maserati or Porsche.

But here we have the new X5, which merrily busts the two principles of fun motoring listed above. It has seven seats, but it isn’t a hopelessly dull MPV (or Multi Purpose Vehicle). And in spite of its wife-approving levels of practicality, it’s a genuine hoot to drive.

From the back it’s hard to tell that this is a new car, but the front end offers several clues, mainly in the more upright grille and the chunkier, more rugged styling. Check out the air vents just behind the front wheels, too. BMW calls them ‘Air Breathers’, and they help to reduce drag. Very racy, and very appropriate as we’ll see.

While the X5 has kept its wheelbase from the second-generation model, this new car is slightly upsized, giving it a bigger boot. (Quick, tell the wife!) There’s 650 litres of cargo haulage on offer if you have the last two seats folded, rising to 1,870 litres if you stow the middle row of chairs as well. That’s a useful 120 litres more than before.

BMW says the two chairs in the back are for people up to 1.50 metres tall, but I reckon I could probably take a short journey back there, and I’m 1.74 metres in height (okay fine, 1.735m). There’s even a small air-con vent for the people consigned to the rear. Access back there is fairly easy too, because you can yank a lever and get the middle chairs to tip forward out of the way.

Those middle seats slide and recline, too, but the BMW’s cabin is so huge you wonder if it’d ever be necessary to adjust them. There’s room to swing two cats in there, and if you have a large, well-fed family, the X5 is BMW’s solution to their transport needs.

But so much for the practical stuff. The X5 comes in three flavours, and this xDrive50i is the hottest of the lot. As before, the bonnet hides a 4.4-litre twin-turbo V8, but the flames have been turned up on this one so the power output rises from the previous model’s 407bhp to a hairy-chested 450bhp. Peak torque is up 50Nm to 650Nm, and it arrives at just 2,000rpm.

Predictably, when you put your foot down in the X5, there’s only the slightest bit of turbo lag before the V8 erupts and the BMW heaves forward with explosive force. It’s a damn heavy car at nearly 2.3 tonnes, but someone forgot to tell the engine, because the X5 picks up speed with all the relentless fervour of an aroused rhinoceros.

There’s a fantastic soundtrack to accompany it all, too. The engine makes traditional thundery V8 noises, as if BMW went to a NASCAR weekend to soak up the sounds and distill them for the X5. This is one of those engines whose voice is so evocatively thrilling that you often find yourself turning the sound system down, just so you can hear the V8 vocals better. The xDrive50i might come with a fancy Bang & Olufsen hi-fi, but no MP3 you play can compare to the music from under the bonnet.

The one sound you’re unlikely to hear from the X5 is that of tyres screeching, at least when you accelerate out of corners. That’s because the BMW has boundless traction. The xDrive system is aimed at customers in snowy, icy places, so it’s unlikely to be troubled by whatever you throw at it here. It’s an active system, too — if the front wheels slip, more power is sent to the rear ones, and so on.

The X5 also has optional torque vectoring. Aim the BMW out of a right hander and the transmission diverts power to the car’s left wheels to tighten up the turn, and vice versa. There’s also an active anti-roll system, so you can attack a series of bends as hard as you like without giving your passengers seasickness.

This lets the big X5 do a credible impression of a hot hatch, and overall it means that the V8’s brute power doesn’t go to waste.

Nevertheless, at some point the X5’s weight does assert itself. The xDrive system might give the car the traction abilities of a lizard, but it only works when you’re on the accelerator and does nothing to help the turn-in process. Still, there probably isn’t a better seven-seater to drive.

The downside is that owning one will make you fast friends with your local pump attendant. The xDrive50i is actually 16 percent less thirsty than before on average, but it still wants 10.5 litres of per 100km. And that’s when you’re going all granny. Use the V8 as God intended, and you’ll discover the extent of its appetite.

Also worth pointing out is that some of the plastics, namely the signal stalks, feel surprisingly cheap. That might seem like a nit-picky complaint, but tax hikes have pushed the xDrive50i’s price to $474,800, and at that sort of money customers expect perfection. And that’s where, in spite of the X5’s outstanding practicality, the wife might grumble a little; 30 Hermes Birkin bags for a car? You must be kidding.

Yet, there’s a happy middle ground available in the form of the xDrive35i, which gets by on a 3.0-litre turbo with 306bhp. It’s slower than the V8 to 100km/h by 1.5 seconds, but my guess is that its lighter engine could give it sharper handling and make it the keen driver’s choice. Or there’s the diesel-powered xDrive30d (258bhp, 0 to 100km/h in 6.9 seconds, 6.2L/100km) if the V8’s fearsome thirst puts you off.

Either of those would cost you $91,000 less than the xDrive50i, which makes test driving different versions of the X5 a worthwhile exercise when you’re shopping for one — with the lesser models you could still end up with a practical, fun car that’s true to its badge, and spend the difference on half a dozen Birkin bags, enough to let you have a new X5 while ensuring marital bliss for a spell. That brings me to another of life’s inviolable laws, which is that women are crazy.

NEED TO KNOW BMW X5 xDrive50i
Engine 4,395cc, 32V, twin-turbo V8
Power 450bhp at 5,500rpm
Torque 650Nm at 2,000rpm
Gearbox 8-speed Steptronic automatic
Top Speed 250km/h (limited)
0-100km/h 5.0 seconds
Fuel efficiency 10.5L/100km (combined)
CO2 244g/km
Availability Now