Cadillac has just announced that the eighth most abundant element in the earth’s crust—magnesium—will be used for wheels on the upcoming Blackwing versions of the CT4-V and CT5-V, and Cadillac notes that “2022 CT4-V Blackwing and CT5-V Blackwing will be the only GM products to offer magnesium wheels in the near future.” Interesting.
First, let’s focus on the magnesium alloy itself. Magnesium is both very strong and very light—it has the highest strength-to-weight ration of any commonly available metal—and that makes it an ideal candidate to reduce unsprung mass in cars without compromising the integrity of the wheels themselves. Porsche has used magnesium wheels on some of its cars in the past (the 918 Spyder and most recent 991 GT2 RS come to mind).
Not only is it lighter and stronger than aluminum, it’s also going to be more exclusive. No other GM products will be getting forged magnesium wheels, according to Cadillac. Don’t let this deject those of you who are eagerly anticipating the next Corvette Z06, for there is another material that’s very strong and very light—carbon fiber.
While the Shelby GT350R and the GT500 with the carbon pack have brought carbon fiber wheels to the world of American performance cars, Cadillac is sticking with good old fashioned alloys for the ultimate version of the CT4 and CT5, and that’s fine. However, this does leave the door open for the next Corvette Z06 (and maybe the next Camaro Z/28, assuming there is one) to really up its game with a set of carbon fiber wheels. They’re more expensive to build and replace than magnesium is, but the Vette is no doubt going to be a more expensive car.
We’ll have to wait until summer of next year to get the full details on the Blackwing cars, but expect the magnesium wheels to be a pricey and rare option when the cars to finally break cover.