The BMW M5 CS may look like a relatively civilized four-door sedan, but BMW has created an absolute animal. Thanks to a twin-turbocharged 4.4-liter V8 producing 627 hp and 553 lb-ft of torque, the M5 CS is the most powerful production M car BMW has ever produced. It's also significantly lighter than the M5 Competition, enabling it to set blistering lap times at the Nurburgring.

Officially, BMW claims the M5 CS will sprint from 0-60 mph in 2.9 seconds and top out at 190 mph. To see if these claims hold up, the M5 CS was set loose on the German autobahn, before which a quick acceleration test was undertaken.

Impressively, the M5 CS recorded a 0-60 mph sprint time of 2.98 seconds, putting it in the same league as a Ferrari 812 Superfast. In the same run, the M5 CS hit 124 mph from a standstill in 9.67 seconds, which is around 0.6 seconds faster than BMW claims. The super sedan also blitzed the quarter-mile in 10.64 seconds, completed the half-mile run in 16.87 seconds, and took 27.36 seconds to cover one mile.

Out on the Autobahn, the M5 CS recorded a GPS-verified top speed of 191 mph - that's insanely fast for a heavy sedan that has a curb weight of 4,114 pounds.

Thanks to extensive use of carbon fiber applied to the spoiler, roof, front splitter, and hood vents among other components, the M5 CS is 230 pounds lighter than the M5 Competition. These performance figures are even more impressive when you consider the tests were performed on a public road on an unprepared road surface.

Being lighter and more powerful than the regular M5, the M5 CS of course carries a significant premium. Pricing starts at $142,000, making it $40,000 more expensive than the regular M5. Whether the performance gains justify the performance gains is up for debate, but it's nice to know the M5 CS lives up to BMW's performance claims in real-world conditions.