September 26, 2006 - Bayerische Motoren Werke really didn't have to build the new M6. The in-house performance elves at its M subsidiary already have a full cupboard of "M'm! M'm! Good!" versions of the 3 Coupé and Convertible, Z4 Roadster and M Coupé and, up until now, the ultimate M car: the 5 sedan-based M5.

As the cooking 6 Coupé is based on the standard 5 sedan, the M6 is fashioned from the oily (and not so oily) bits of the M5 uber-sedan.

There's the same 500-horsepower, 360-pound-feet-of-torque V10 engine that revs like the Formula One engine that inspired it; there's the same no-clutch-pedal, seven-speed sequential manual transmission and gear ratios and the same all-aluminum suspension that reads the tarmac better than a road's scholar.

So, then, why a hyper-performance version of what most critics would already agree is a very nice performing car in the grand touring 650i Coupe? And what delicacies does the two-door M6 bring to the driving enthusiast's table that the four-door M5 hasn't already delivered beyond the all-too-obvious coupe form?



Like the M5, once you and a friend (you really wouldn't put anyone you care for in the back seats) are snuggly ensconced in the M6's generously wide cockpit, you're greeted with a similar variety of variable electronic doo-dads for the transmission, suspension and engine. But only two buttons must be considered before you head out of your driveway.

Don't forget to push the "power" button. It unleashes the Herculean V10's full 500 ponies instead of being reduced by 100 for valets, brothers-in-law or teenaged drivers.



Next is a button on the steering wheel called M Dynamic Mode. Via the iDrive controller, MDM adjusts everything from dynamic stability control response to how sharply the gearbox shifts quickness. After that, it's time to find a half-decent road. Choose one that traverses wide-open spaces because, like the demonic, four-door M5, the M6 Coupe can easily reach the same governed 250-kilometres-an-hour top speed. Not that I would know, because that would be illegal ...

Although the V10 motor sounds a bit truckish at low revs, once you have the space -- and the courage -- to take it to its nearly-8,000-rpm limit, it's as if the laws of friction and gravity cease to exist. When set at its most aggressive setting, the transmission changes gears with the ferocity of a cracked whip.



And when you do experience driving annoyances such as slower traffic, simply drop the tranny a couple of gears via the steering wheel-mounted shift paddles, plant your right foot and don't forget to wave.

By sharing the same drivetrain, the M6 isn't any more powerful. But BMW claims it out-accelerates its M5 to 100 km/h by 1/10th of a second at 4.6 seconds. That slim edge is mainly achieved by engineers slimming the M6 itself, as if it was a boxer trying to make weight.

How? First off, the M6's roof is a slim slice of carbon-fibre- reinforced plastic, an idea that was first employed on the Euro-only limited-edition M3 CSL. For those of you keeping score at home, it's 55% lighter than the standard 650i Coupe's tin top. And beyond the gee-whiz factor, it also lowers the car's centre of gravity by nearly three millimetres. Even the bumpers use the same high-tech material. Side panels and the rear decklid are now lightweight fibreglass-reinforced plastic, and those thinly spoked 19-inch rims shave another 1.81 kilograms at each corner.



It all adds up -- to the point where the M6 weighs 47 kg less than the M5. And the M6's slim advantage in straight-line capability over its four-door M sibling exponentially grows when it's time to change directions.

If you're looking to justify yet another BMW M car, think about the M6's broad capabilities.

Although it's not the curve carver that the lighter and more nimble Z4-based M Coupe is, the M6's lower centre of gravity allows you to play boy racer where the M5 requires a more concerted mental effort to stay out of the weeds.

Technically, the M6 is still a grand tourer. But, when you're done defying physics, you can turn down the volume on the various settings, drape one hand over the steering wheel and cruise. In this Perry Como mode, the M6 loses its hard edges and cossets contently.

- John LeBlanc, Publisher, www.straight-six.com

THE SPECS
TYPE OF VEHICLE Rear-wheel-drive sports coupe
ENGINE 5.0L DOHC V10
POWER 500 hp @ 7,750 rpm; 383 pound-feet of torque @ 6,100 rpm
TRANSMISSION Seven-speed sequential manual
TIRES 255/40ZR19 (front), 285/40ZR19 (rear)
BRAKES Four-wheel ventilated disc with ABS
PRICE: BASE/AS TESTED $130,500/same
FUEL ECONOMY L/100 km 11.5 city, 7.5 hwy.
STANDARD FEATURES Adaptive headlights, dual-zone temperature controls, leather upholstery, heated front seats, headlight high-pressure washer system, heated exterior mirrors, electrically adjustable multi-function leather steering wheel, Park Distance Control, auto-dimming rear-view mirror, rain-sensing wipers with heated washer nozzles, tire pressure warning, xenon headlights.

© National Post 2006. This article originally appeared in The National Post's Driving.