MILFORD, Michigan — When Inside Line learned it would have access to a 2009 Cadillac CTS-V at GM's Michigan proving grounds, we packed up our portable Racelogic VBOX III testing gear and booked our staff hot-shoe on the next flight to Detroit.After spending time behind the wheel of Cadillac's powerful new sport sedan, we weren't disappointed. The 2009 Cadillac CTS-V, equipped with a supercharged 556-horsepower 6.2-liter V8 and a six-speed manual transmission, accelerated from zero to 60 mph in 4.6 seconds (4.3 seconds with 1 foot of rollout like on a drag strip) and crossed the quarter-mile in 12.5 seconds at 115.3 mph.That's a faster quarter-mile sprint than either the 500-hp 5.0-liter V10-equipped 2007 BMW M5 or the 507-hp 6.2-liter all-aluminum V8-equipped 2007 Mercedes-Benz E63 AMG achieved. The two German super sedans both took 12.7 seconds to cross the quarter-mile marker and did so with trap speeds of roughly 113 mph.The Caddy's braking distances and slalom speed were even more impressive. The CTS-V stopped from 60-0 mph in just 109 feet, bettering the M5 by 5 feet and the E63 AMG by 6 feet. The CTS-V also managed to break the 70 mph barrier in the slalom with a best run of 71.1 mph. The BMW M5 ran 68.5 mph, while the E63 only managed 65 mph.Acceleration:0-30 mph — 2.1 seconds0-45 mph —3.2 seconds0-60 mph — 4.6 seconds0-75 mph — 6.3 seconds1/4-mile — 12.5 seconds at 115.3 mph0-60 mph with 1 foot of rollout — 4.3 seconds Braking:30-0 mph — 27 feet60-0 mph —109 feet Slalom (600 feet)— 71.1 mphSkid pad lateral acceleration (200 feet) — 0.92gWhat this means to you: GM product head Bob Lutz promised that this CTS-V would put the M5 on the trailer. According to our test numbers, he's right. — Kelly Toepke, News Editor