| First Drive | Road Atlanta, Georgia, USA | BMW X6 M |

At the launch of the BMW M3, almost two years ago to the day, I asked Gerhard Richter, the then head of development at BMW's M Division, if BMW was ever going to diversify the M brand as Mercedes had done with AMG. His answer was unequivocal: "Never" he thundered, "M cars need to be rear-wheel drive, normally-aspirated, sporty cars." I sighed in relief: M Division was safe. But here we are, some two years and one global recession later, driving an car that's just about everything BMW said it would never make - an all-wheel drive SUV with an automatic transmission powered by a turbocharged engine based around a stock V8 block.

Needless to say Herr Richter is gone; he has been promoted to head of development for the new 5 Series Gran Turismo - while his replacement, Albert Biermann, steers M division in a new, more pragmatic direction. And who can blame BMW for cashing in a little M equity? Mercedes has slapped an AMG badge on just about everything it makes, so why can't BMW make its M cars a little less bespoke, a little more profitable? Times are tough, after all, and above all else, M Division has to make money to survive. But an X6 M? Is that really what the world needs right now?

In the Metal

Mock the silliness of the X6 all you want, but BMW's unfortunately titled "Sport Activity Coupé" or "SAC", has been a runaway success for the company, forcing them to triple output to meet demand. Because it's such an aggressive and muscular car to begin with, BMW hasn't had to change that much of the X6 to transform it into the X6 M, which is good news for a company trying to squeeze as much profit as it can from its newest model.

The X6 M shares most of its sheet metal with the standard X6, including the bonnet, doors, rear wings, boot lid and roof, although it does get new front wings incorporating fake cooling gills, new 20-inch alloy wheels and new side skirts. 'Round back there's a new bumper, roof spoiler and two dual exhaust outlets and that's about it, really. You can forget about getting a carbon fibre re-enforced plastic roof panel here; cutting a few kilograms from a two-tonne car is a bit like ordering Diet Coke with your super-sized Quarter-Pounder meal.

Meanwhile, the interior of the X6M is no more bespoke than the exterior. The seats get a tiny bit more shoulder bolstering, but otherwise they're the same as the stock X6's, while the addition of an M button on the steering wheel, a pair of aluminium pedals, the M5's head-up display and dials, some blue and red stitching here and there, plus a smattering of M badges completes the X6 M's interior revisions. Feeling a little underwhelmed so far? So was I.

What you get for your Money

Compared to the £90,000 Porsche Cayenne Turbo S, which offers almost identical performance figures to the ballistic X6 M, the BMW's £77,425 price tag doesn't seem like bad value at all. Powered by a 547bhp, 501lb.ft, twin-turbo 4.4-litre V8, the X6 M can reach 62mph in just 4.7 seconds and top 171mph if you opt for the Autobahn-oriented "M Driver's Package", which means it's pretty much toe-to-toe with the Porsche's 4.8-second 0-62mph time and 174mph top speed.

However, for around £75,800 you can opt for either the Mercedes-Benz ML 63 AMG or the non-S Cayenne Turbo, neither of which are quite as fast as the X6 M, perhaps, but they aren't exactly slouches either, being capable of hitting 62mph in 5.0 and 5.1 seconds and topping 155mph (limited) and 171mph respectively. In terms of overall bang-for-your-buck, then, the BMW X6 M seems to be the class leader. Standard specification is generous, too, with 20-inch alloys, adaptive dampers, leather upholstery, parking sensors, electric sport seats and satnav all standard.

Driving it

You really do have to marvel at the technical wizardry that allows a 2,380kg off-roader go, stop and corner like this X6 M does. The suspension is fitted with stiffer bushings, bearings and sub-frame mounts while the standard air suspension's springing and damping is set up more aggressively. Adaptive shocks, with an active anti-roll system, as well as self-levelling rear suspension, are also standard and the power steering has been recalibrated, although a variable-ratio steering rack is not available because it apparently isn't in keeping with the M philosophy. Huge 395mm discs and four-piston brake callipers are fitted to the front wheels, with 385mm discs and single-piston callipers at the rear.

The X6 M is also the first M car to get a six-speed automatic transmission, although the gearshift times are faster and in high-performance 'M' mode there is no automatic up-shifting at the rev limiter. Steering-wheel mounted paddle shifters and 'Launch Control' are standard, as is a computer-controlled multi-plate central differential. BMW's re-tuned "Dynamic Performance Control" rear differential completes the dynamic revisions, ensuring maximum traction by accelerating the wheel with the most grip rather than braking or cutting power to the slipping wheel.

Perhaps unsurprisingly, then, the X6 M is a staggeringly competent, but rather soulless thing to drive on the road. The engine, a heavily modified stock unit, remember, makes a muted and characterless noise and while forward propulsion is impressive, it's not quite expletive-inducing. The transmission left us equally as cold: it shifts quickly and smoothly but it's not the most responsive unit in the world and yanking on the steering-wheel paddles doesn't speed things up any. The ride quality is impressive though, particularly when you consider it's riding on 20-inch wheels, but there's not too much feel up through the chassis and while the steering is sharp and quick for an off-roader, it's unlikely to give you goose-bumps. Grip, as you'd expect, is abundant and the X6 M's brakes are astonishingly powerful and while there's a reasonable amount of steering and brake feel too, ultimately any kicks you get from driving the X6 M are derived from the fact that you're bending the laws of physics in a two-and-a-half-tonne SUV rather than from pure driving pleasure, as you find in other M cars.

Having said that, there is a sadistic pleasure to be derived from spanking the X6 M around a racetrack that is difficult to ignore. You may not be feeling every inch of asphalt with your buttock hairs but you're still grinning like a buffoon simply because the whole experience is so utterly incredible. The X6 M has seriously benign on-limit handling characteristics that fill you with confidence and allow you to attack the track with alarming vigour.

Just as importantly, it's also staggering robust; we drove our X6 M from the centre of Atlanta to the punishing and technical Road Atlanta race circuit, drove the socks off it (without even altering the tyre pressure) until it literally ran out of fuel and then turned it around (once someone from BMW kindly re-filled the 85-litre tank) and drove back in it without so much as a whimper of complaint from the tyres, brakes, engine or transmission. It shrugged off kerbing as if it wasn't even there and repeatedly slowed down from 145mph to 55mph on a short, steep, downhill section of track without falter all afternoon. Sadly, few owners will ever experience just how remarkable the X6 M truly is and will only know the car's rather uninspiring on-road characteristics.

Worth Noting

The X6 M's V8 engine block is stock, but the cylinder head, pistons and con-rods are all new, while the turbos and catalytic converters (not to mention the coolant reservoir) are located in the V between the cylinder banks and an innovative single exhaust manifold is used to ensure throttle responsiveness and efficiency at every engine speed. A special exhaust flap also changes the exhaust note in M-mode.

Despite weighing 2.4 tonnes, the X6 M can reach 100km/h in a staggering 4.7 seconds and top 155mph - that's precisely as fast as the current BMW M5 and M3, which weigh a whopping 550- and 700kg less respectively. Despite fitting brake energy regeneration, an on-demand electric fuel pump and a de-coupling air conditioning compressor to improve efficiency, the X6 M's combined-cycle fuel consumption figure of 20.3mpg and a CO₂ output of 325g/km means you'll have to live in freezing darkness and eat grass clippings to offset your carbon footprint.

Summary

Sure, the X6 M is silly and pointless, but if we're completely honest with ourselves, what performance car really makes sense? The X6 M is an astonishing piece of engineering, no question, and while it's no M3 on the road the X6 M is a bit of riot on the racetrack - more so than many performance cars you'd expect to shine on the track. Alright, I will concede that very few people are ever going to use an X6 M that way, but it's not like anyone takes their off-roaders across the Serengeti either, now do they?

Purists will balk at the X6 M for besmirching the reputation of BMW's revered M Division, but they should bear in mind that high-profit cars like the X6 M help fund the stuff we really want to drive, like the M3 CSL that was canned when the recession hit. In addition, the willingness of M Division to modify stock engines and transmissions also increases the likelihood of cars like an M-version of the 1 Series finally making it to production, so while the X6 M on the face of it seems like the antithesis of everything BMW's performance division once stood for, it could ironically, be the key to the M's continued long-term survival.