Revised from rubber to roof

Starting with its carbon-fiber roof and ending at the 19-inch alloy wheels wrapped in sticky Continental Z-rated rubber, BMW’s Motorsport Division has performed a top-to-bottom revamp of the 6 Series coupe in creating the M6. At just over 3,900 pounds, the M6 is not exactly a featherweight contender, but that carbon-fiber roof both enhances the coupe’s appearance and lowers its center of gravity. Powered by a 500-horsepower V10 and hooked to a seven-speed Sequential Manual Gearbox (SMG) transmission, this nearly 2 tons of Munich machinations can sprint to 60 mph in 4.6 seconds and blast through the quarter-mile in 12.8 seconds at 117.4 mph. Coincidentally, 12.8 was also the mpg we averaged during the course of the M6’s road test.

High-performance engine, high-maintenance tranny

As with the high-grade plastic roof, the M6’s 5.0-liter aluminum V10 engine could serve as the centerpiece in a Wired magazine article on the future of automotive technology. Designed as a high-revving homage to BMW’s own F1 engine design, its maximum horsepower is achieved at an ear-pleasing 7,750 rpm (redline occurs at 8,250 rpm). Another common characteristic associated with high-rpm engine designs (à la Honda’s S2000) is a maximum torque figure that is markedly lower than the maximum horsepower figure. With 383 pound-feet available at 6,100 rpm, this V10 doesn’t pull like the one found in the Dodge Viper. However, advanced features like Double VANOS variable valve technology, a 12:1 compression ratio and 10 individual throttle bodies (one for each cylinder) give the V10 an addictive combination of smooth and flexible power delivery – despite its high-revving nature.

Complementing the V10’s broad power band is the same seven-speed SMG transmission found in BMW’s M5 sedan. But where the V10 is an unmitigated success in using modern technology to enhance the driving experience, SMG is … well, mitigated. It’s another bit of F1 technology passed down from BMW’s race team, and it offers the usual promise of rapid-fire, rev-matched downshifts, crisp upshifts and even a computer-modulated “Launch Control” mode that can maximize throttle and clutch activity for near flawless acceleration runs. All of these features occur with the SMG in “Sequential” (or fully manual) mode, and it’s under these circumstances that cutting-edge technology is the driver’s friend.

But the SMG also holds out the promise of “Automated” shifting, meaning fully automatic gear swaps with no driver interaction required. Technically the promise is fulfilled, as selecting “D” does free the driver from using either the steering wheel paddles or the shifter to initiate gearchanges. Yet the reality is closer to Michael Jackson’s nose – it works, but nobody likes it. Beyond the obligatory head toss that all of these systems cause (Audi’s DSG being the sole exception), we were often disappointed by the SMG’s indecisive nature when rolling into the throttle at low to medium speeds.

In one specific case we were trying to turn across oncoming traffic. When our opening came, we stomped on the throttle only to have several panic-stricken moments of nothingness occur before SMG finally picked a gear and sent power to the rear wheels. One might question the use of “Automated” mode when trying to cross a busy street, but if the automatic mode can’t be depended upon in heavy traffic, what’s the point? Several additional functions, like “Start-Off Assist” to keep the car from rolling back on inclines and “Overspeed protection” to prohibit gear choices that would damage the engine, are welcome features. But most editors would have gladly traded them all for an old-fashioned clutch pedal. Thankfully, BMW will offer a traditional manual transmission on both the M5 and the M6 by fall of ’06.

A car that begs to have its buttons pushed

After several SMG misfires the crotchety old man in us was almost ready to trade in the M6’s keys for a Matlock season-three DVD boxed set. But then we started playing with the MDrive system. This is a menu within the iDrive system that allows the driver to pick from the three engine power settings, 11 SMG tranny settings, three suspension settings and three dynamic stability control settings. Because not every setting is available with every other setting, the total number of driving mode combinations comes out to 279. The MDrive menu can also be used to configure the M head-up display, creating a virtual tachometer and gear indicator at the base of the windshield. If it all sounds like too much to keep track of, just remember that, once you configure the “M” button on the steering wheel, you can put the M6 into your preferred driving mode by simply hitting said button.

The default power setting for the engine is “P400” and, as you might guess, it supplies 400 peak horsepower. You can also pick “P500” by pressing a center console button to access all 500 hp the V10 is capable of producing. However, if you want maximum horsepower and maximum throttle response, then you want “P500 Sport” – a setting you can only access using the MDrive menu and the M button on the steering wheel.

As for the suspension and stability control settings, these are also adjustable via buttons on the center console. We were particularly impressed by the M6’s Electronic Damping Control because, unlike so many “adjustable suspension” vehicles we’ve driven, the M6’s ride and handling characteristics really do change at the push of a button. The “Comfort” setting is indeed comfortable for everyday driving without feeling overly flaccid, and the “Normal” setting is well suited to attacking canyon roads or cloverleaf entrance ramps. We tried the “Sport” setting and felt it was generally too stiff for public road use. In this mode, midcorner bumps would actually upset the car’s balance, and we found ourselves switching back to “Normal” mode on all but the smoothest pavement. But for track purposes – or instrumented testing on our slalom course – “Sport” proved ideal, and allowed the 3,900-pound M6 to slither through the cones at 67.1 mph.

Braking maneuvers are similarly well managed by ventilated and cross-drilled rotors, sized 14.7 inches in front and 14.6 inches in back. Yet more high-tech features come in the form of “Brake Standby,” a system that senses rapid throttle lift and immediately snugs the brake pads up against the rotors in anticipation of emergency braking. A similar function, dubbed “Brake Drying,” brings the pads in contact with the rotors on a periodic basis whenever the windshield wipers’ rain sensor is activated. This keeps the pads dry and ensures maximum braking, even during inclement weather. If all that is too much to take in, just remember that our 60-0 brake testing showed no sign of fade after five panic stops, and it had the M6 halting in a confident 111 feet.

Luxury remains a primary ingredient

Beyond its undeniable performance capabilities, BMW imbues the M6 with a palatial cabin featuring a multitude of luxury items. Our test car was outfitted with the optional “Full Leather” package that lays down supple Merino leather on everything that isn’t already wood or metal. The 10-way, power-adjustable seats remain comfortable after several hours and hundreds of miles behind the wheel and the high-quality switchgear lives up to the six-figure price of entry. The technology theme continues inside with standard DVD navigation, voice command, a 13-speaker Harman Kardon Logic 7 audio system and a built-in Bluetooth cell phone interface.

 By Karl Brauer