Back in June, we spied a curious Cadillac CT5-V Blackwing prototype with what we thought was a bronze wheel package. Then in October, Cadillac officially announced that the CT5-V Blackwing and CT4-V Blackwing models will offer magnesium wheels as an option, providing a teaser that did not show the entire wheel. And that’s when it all made sense: what we thought were bronze wheels were actually the upcoming mag wheels.
The magnesium wheels on the CT5-V Blackwing prototype are 19 inches in diameter and have a multi-spoke design with a satin bronze finish that contrasts nicely with the red brake calipers behind them. They are wrapped with Michelin Pilot tires measuring 275-30 at the front and 305-30 at the rear, which is wider than the rubber fitted to the third-gen CTS-V high-performance sedan.
Since magnesium has the highest strength-to-weight ratio of any metal which could reasonably be used for making wheels, the optional rims are lighter than the stock aluminum items. This will help in the handling department, and to some extent their straightline performance. A possible disadvantage is that lower unsprung weight usually leads to inferior ride quality, but this could be compensated by the fact that magnesium has a high damping capacity. In other words, it converts movement into heat, which is rapidly dissipated by the surrounding air.
With or without magnesium wheels, the Blackwing models will be the high-performance variants of the CT4-V and CT5-V. The Blackwing name was previously used for the twin-turbo 4.2L LTA V8 engine which was rated at 500 horsepower and 553 pound-feet of torque when fitted to the discontinued Cadillac CT6 4.2TT Platinum and 550 horsepower and 627 pound-feet in the CT6-V.
However, neither of the new models will use it. The CT4-V Blackwing will get a twin-turbo 3.6L V6 similar to the LF4 used in the last-gen ATS-V, where it was rated at 464 horsepower and 445 pound-feet the CT5-V Blackwing will be powered by a supercharged 6.2L V8 similar to the LT4 used in the aforementioned third-gen CTS-V, where it produced 640 horsepower and 630 pound-feet. The CT5-V Blackwing will be capable of reaching a top speed of over 200 mph. Both engines will be mated as standard to a 6-speed manual transmission or to an optional ten-speed automatic.
Cadillac has said that the decision to offer magnesium wheels on these cars was inspired by the fact that similar items are also fitted to the Cadillac DPi-V.R race car. The DPi-V.R has won the Prototype class of what is now known as the IMSA WeatherTech SportsCar Championship every year since 2017.
The CT4-V Blackwing and CT5-V Blackwing are both set to launch in the summer of 2021 as 2022 model year cars. Both will offer the magnesium wheels as an option.
This post was written in collaboration with our sister publication, Cadillac Society.