Power is delivered to the rear wheels through a remarkably rapid eight-speed automatic transmission. The rear differential is the electronically controlled kind and driveshafts are asymmetric, developed specifically to avoid the dreaded axle hop under hard straight-line acceleration.
Chassis improvements make for a 25 percent stiffer bodyshell and the CTS-V is suspended by GM’s third-generation Magnetic Ride Control dampers. Brakes are six-piston Brembos up front and four-piston at the rear.
While the rear brake discs are single-piece items, the fronts are two-piece, 390mm diameter rotors. Michelin Pilot Super Sport tyres are fitted - 265mm wide at the front with 295mm at the rear.
The clean lines of the interior are similar to all other Cadillac models, with delta shapes dominating your view, no matter where you turn. Available as an option are 16-way adjustable Recaro front seats, but the large, high-backed buckets take their toll on rear leg room.
The CTS-V is differentiated externally from the standard car by its aerodynamic bodywork. A standard carbonfibre hood includes a central extractor for both heat and lift-reducing airflow, and the wings grow to accommodate wider wheels.
The front fascia has a deeper splitter and larger grille openings to support the increased cooling demands of the 640bhp powertrain. The bootlid is fitted with a tall spoiler for 200mph stability, but the optional Carbon Fibre Package increases the size of both the spoiler and the front splitter.
Reining in all 640 horses is intoxicating, and running down the long front straight of the Road America circuit, the CTS-V continues to accelerate hard past 150mph before being forced to brake for the 70mph first turn. Achieving Cadillac’s claimed top speed of 200mph seems to require only a few more seconds.
For better lap times, the transmission is best left to shift for itself using Sport or Track modes or any of their various sub-modes. Shifts are dual-clutch rapid and downshifts are both swift and rev-matched. Enthusiastic road driving, on the other hand, demands the use of the magnesium shift paddles.
The brakes live up to their promise, performing the repeated high-speed decelerations that Road America demands, and braking effectiveness was consistent over multiple flying laps. For any other car, a recommendation to change to higher-performance brake fluid would be in order, but it’s impossible to imagine any CTS-V owner over-taxing these brakes.
On track, the CTS-V doesn’t display any bad habits, from transitions to steady-state, on-limit cornering, and it's remarkably well balanced. Much credit of the saloon’s confident handling is due to the latest version of GM’s Magnetic Ride Control dampers, which have well-defined modes.
In the firmer modes, body and wheel motion is well controlled to keep the Michelin Pilot Super Sports in contact with the road surface, while a comfortable ride is the priority in touring mode.
The cabin is finished with carbonfibre and Alcantara trim. It can be optioned with even more Alcantara, including the headlining, as well as the steering wheel and shifter.
The digital gauge panel is revised for CTS-V, while the rest of the dash is familiar Cadillac, including the CUE infotainment unit. If you’re the 'set it and forget it' type, the voice activation features work flawlessly and keep the driver’s concentration on the road.
Front-seat passengers enjoy the comfort of the optional Recaro buckets, but the seats seem like they could benefit from another inch of travel lower to the floor. On track, support is remarkably good, too, with credit due to the aggressive bolstering of the seats and generous amounts of Alcantara upholstery.
As for the rest of the standard equipment, the CTS-V comes with ventilated seats, a 360-degree camera system, forward collision alert, lane departure warning, rear crossing traffic alert, and Cadillac's infotainment system complete with sat nav, wireless phone charging, GM's OnStar system, smartphone integration and a Bose sound system.
If numbers are your thing, the CTS-V beats the now defunct BMW M5 and Mercedes-AMG E 63 in both power output and top speed. It'll accelerate from a standstill to 62mph in less time, too. That said, while being bigger and brasher is fine, the CTS-V can't match the handling precision of its German competition.
To many, though, it’ll be that unmistakable American style that makes the CTS-V appealing. It has the presence of a body builder in a tailored suit and has the performance to match its looks.