Dimensionally the 10-cylinder is not huge. The 5.0-liter displacement equates to 305 cubic inches. The 500 horsepower peaks at 7,750 rpm, the 383 foot-pounds of torque at 6,100 rpm. By comparison, the Audi S6 V-10 hits its 435 peak horsepower at 6,800 rpm and peak torque at 3,000 to 4,000 rpm. You feel the love sooner in the Audi.
The treasure hunt for the M5's power is in its naturally aspirated, high-revving powerband. To achieve 0 to 60 in 4.5 seconds, get on it, stay on it and keep on it.
The seven-speed SMG automated-manual is the standard transmission, which might be desired for ease in commuting traffic. Not so, really. The manual's shift pattern is foolproof and the action inspiring. There's enough power in second gear that the engine can lug down to near zero, but with a push on the accelerator it will pull up to speed and then go on to exceed any national speed limit. An electronic hill-holder function ensures smooth starts on hills, and a full array of safety features will prevent accidental stupidity.
The manual has a steep first-gear ratio that climbs to the peaks in a hurry. And because the manual is a close-ratio box, it has close shift-recovery points. When you shift at the peak horsepower point of 7,750 rpm, the next gear places the engine right into its torque peak, which is near 6,100 rpm. So, when you're in the next gear, you've got peak torque available under your right foot. No need to rush gears, just keep it revving and max horsepower comes right back up.
It's a delicious experience and once you've found this buffet line you'll be back often. The engine sound at high revs is an aircraft roar, different from other V-10s. And at idle it sounds much lighter weight, more like the Dodge Viper.
The acceleration advantage goes to the M5 because it is 500 pounds lighter than the S6. But expect more horsepower wars. BMW can supercharge its 4.4-liter V-8 and get 500 horsepower. Audi gets 435 from a 5.2-liter V-10, so there's opportunity to raise the limit.
But as a BMW spokesman said: "There is no horsepower limit that physics (and insurance companies) can't enforce."
For many owners, this car's ability will be several hands above their current level. But those hands have a caring way to lift drivers to a higher ability. And what fun new owners will have finding those limits. I hope that a high-performance driving course already would be under their belts or in their immediate future. To own this car and not be able to appreciate its fine engineering would be a waste of money and the car.
And things happen quickly when this engine is revving near redline. "Is traffic slow today or is it just me," I pondered. And it was just me unable to keep my foot out of it.
The throttle is electronic and feels directly connected with an absolute response. Nothing like the electronic lag in the S6. Steering force is light but communicative. Even when charging through a corner and the weight is on the front tires, it takes just thumbs and forefingers pinched on the chunky steering wheel to maintain control. No maker does that like BMW.
The only similarities between the Audi S6 and M5 are in the 10-cylinder engine. It is unlikely a BMW enthusiast would buy an Audi, but he or she would certainly like to have seat time in the S6 just to see what he's missing.
The BMW iDrive for audio, heat-air and other car controls is too complex to become handy with in a week. I ignored it and listened to whatever radio stations were preset. Audi and Mercedes-Benz have much simpler systems.
However, the wipers have the best clearing swipe of any car I've tested. Or maybe it's the glass.
The optional Merino leather is a handsome treatment and the multi-function seats may be the most accommodating of any manufacturer. But those extras add $5,400 with another $800 for ventilated seats. The $1,000 head-up display, a digital readout, isn't effective in all light conditions and can't be adjusted up or down - something even General Motors has accomplished for a lot less.
The M5 exterior treatment is as lean as the interior. Enthusiasts will spot the badges and recognize the air-scooping front valance, side sills and the quad-tip exhaust tips, which have Skunk Works originality. It's almost as if they don't fit quite right and the open rear valance looks like it needs a section of honeycomb grille to complete the design. For those who can afford a $100,000 sports car, some of these gripes might be deal breakers. But the spirit of the car will prevail.
The S6 is khakis and Cole Haans.
The M5 is denim, driving shoes and skipping work to enjoy the buffet.
SPECS
2007 BMW M5
Body style: midsize, rear-wheel drive, five-passenger sedan Engine: 5.0 liter, 40-valve V-10 with variable valve timing, g-sensitive lubrication and electronic throttles
Horsepower: 500 at 7,750 rpm
Torque: 383 at 6,100 rpm
Transmission: seven-speed Sequential Manual Gearbox or no-cost-option 6-speed manual
Acceleration: 0 to 60 mph, 4.5 seconds
EPA fuel economy estimates: 12 mpg city, 18 highway (either transmission)
Length/wheelbase: 191.5/113.7 inches
Curb weight: 4,012 pounds
FEATURES
Safety equipment includes: dynamic stability control with all-speed traction control, electronic brake proportioning, ABS, cornering-braking stability enhancement, dynamic brake control, brake drying
CHASSIS
Brakes: four-wheel ventilated and cross-ventilated discs; 14.7-inch front; 14.6-inch rear
Steering: Servotronic vehicle-speed sensitive with comfort and assist levels; 40.7-foot turning circle
Suspension: aluminum with struts, double-pivot lower arms, coil springs, electronically twin-tube, gas-charged shock absorbers with normal, comfort and sport modes and stabilizer bar; rear, aluminum four-link with coil springs, electronically twin-tube gas-charged shock absorbers with normal, comfort and sport modes and stabilizer bar
Tires and wheels: 255/40ZR 19-inch front; 285/35ZR 19-inch rear; alloy wheels; flat-tire tire air pump and sealer
PRICING
Base: $83,195, including $695 freight charge; price as tested, $97,590, including $3,700 gas-guzzler tax.
Options on test car: Silverstone II perforated Merino leather, $3,500; comfort access system, $1,000; multifunction front seats with lumbar, $1,900; head-up display, $1,000; power rear sunshade with rear manual side window shades,$575; front ventilated seats, $800; split, folding rear seatback with ski-bag pass-through, $475; heated rear seats, $350; HD radio, $500; satellite radio, $595
The competition: Audi S6, Cadillac STS-V, Jaguar XJR, Mercedes-Benz E63.
Where assembled: Dingolfing, Germany
PLUSES: A supersedan with deceiving ability.
MINUSES: The M5 is not demonstrative in its power, noise or sophistication. At nearly $100,000 a performance enthusiast could celebrate midlife with the 425 hp, V-8 powered, all-wheel-drive Audi RS4 ($67,000 with options), pick it up at the factory in Germany, vacation for a month and drive on the autobahn and Nurburgring. Not that M5-intenders couldn't that, too.
Mark Maynard is driving in cyberspace at mark.maynard@uniontrib.com.
