ALTON, Va.—Cadillac is in the process of transforming itself into an electric-only brand, with the first of its electric vehicles due next year. That means the end for the high-performance V-series versions of its cars, at least until General Motors develops a performance version of its forthcoming Ultium battery technology. In the meantime, the engineers responsible for those V-series cars have just finished their final projects. Last week, we discussed the outstanding track manners of the CT4-V Blackwing sedan. Today, we’re looking at its bigger sibling, the $84,990 CT5-V Blackwing.

“This is our last intended internal combustion engine version of the family here. We really felt like we wanted to go out on a high note,” said Tony Roma, Cadillac’s chief engineer. “The results, especially with the CT5, are the fastest, most powerful Cadillac we’ve ever done, by a longshot,” he said. And he means it. The hand-built, supercharged 6.2 L V8 provides the CT5-V Blackwing with 668 hp (498 kW) and 659 lb-ft (893 Nm), which translates to headline performance numbers like 0-60 mph in 3.4 seconds and a top speed that Roma says is “well over 200 mph” (321 km/h). Not bad for a midsize sedan that weighs 4,123 lbs (1.870 kg).

To go with the hugely powerful engine, Cadillac has added massive brakes—398 mm rotors at the front and 374 mm at the rear—which, thanks to improvements like a dedicated parking brake caliper, helped the CT5-V Blackwing’s engineers lose 65 lbs (29 kg) of unsprung mass from the car. For those who want to shed even more rotating mass, or maybe just don’t like dealing with brake dust, there’s also now an option of carbon ceramic rotors instead (400 mm front, 370 mm rear).

The chassis has been strengthened and stiffened over the not-V version of the CT5, and the suspension uses the same fourth-generation Magnetic Ride Control magnetorheological dampers as the CT4-V Blackwing—Cadillac says this is the fastest-reacting suspension in the world. During the car’s development, Cadillac put prototypes through thousands of hours on kinematic rigs and then hundreds of laps of test tracks (including 12- and 24-hour durability track tests).

You get a choice of six-speed manual or 10-speed automatic transmissions, as with the smaller call. The 10-speed starts at $88,165, but that price includes some equipment you can’t get with the three-pedal car, including adaptive cruise control, lane keeping, and physical controls for the touchscreen infotainment system. But you do get a gearbox that Roma says will change gears faster even than Porsche’s PDK dual-clutch transmission.

The end result is a sports sedan that is almost mind-bendingly fast on track. We spent the morning lapping CT5-V Blackwings at Virginia International Raceway, a day after getting re-acquainted with the track thanks to the CT4-V Blackwing. The smaller sedan was relatively subtle, while the bigger CT5-V was a much more bombastic experience.

VIR’s front straight might be more accurately called the front parabola, as it arcs around from turn 17 to turn 1. With a decent exit from turn 17 and my foot flat on the throttle, my brain was able to register the fact that the heads-up display showed 141 mph (226 km/h) as I crossed the start-finish line, pulling some healthy lateral Gs in the process. I have no doubt that the CT5-V Blackwing would reach 160 mph (257 km/h) before the first brake marker had I kept my foot down, nor that the big brakes would do their job.

As it turns out, 141 mph in a four-door sedan is actually fast enough for me, particularly when the only stakes are the potential embarrassment (or worse) of binning the car. Similarly, I found I had to brake before the Climbing Esses to avoid entering this challenging uphill left-right-left sequence at more than 130 mph (209 km/h). And without the temporary chicane on the long back straight, I imagine the CT5-V Blackwing would easily top 170 mph before braking for turn 13.

Despite the immense speed it’s capable of, the CT5-V Blackwing was remarkably well-mannered on track. Even with the Performance Traction Management system in its most permissive setting (Race 2, which only intervenes to control traction on corner exits) the car is stable and balanced as long as you’re not a complete idiot with the throttle pedal.

Unlike the smaller car (where the automatic transmission is the way to go), I think I’d pick the manual CT5-V Blackwing over the 10-speed car. You lose some gadgets, and the six-speed will be slower in terms of lap times. But it’s also more engaging at lower speeds, and its no-lift upshift feature and rev matching on downshifts both work very well. My concerns about using the car on the street are the same as they were for the CT4-V Blackwing, except magnified: It’s too fast to enjoy properly and too thirsty to be a daily driver.

But to be honest, I think the CT4-V Blackwing hits the sweet spot. In the CT5-V Blackwing, you arrive at corners so much faster and have to brake harder, plus there’s the extra mass of the car to deal with. I’m not denying that it’s a lot of fun—it is—and it’s very drivable for a car with so much power being sent to the rear axle. But the smaller, cheaper, lighter car is more exploitable on track and on the road.

Listing image by Jonathan Gitlin

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