Growing up in Brooklyn, when the American muscle car was taking over the street, you weren’t tough if your nose-down ride didn’t have mags on it. You know, custom wheels, maybe bought at a place like R&S Strauss, the absolute hot ticket being the Cragar S/S. The wheels took their nickname from the original magnesium wheels, even though they didn’t contain a single grain of magnesium, just lots of chrome plating. It was kind of an insult to real magnesium wheels. Magnesium is the lightest structural metal in existence, which means you can cast a wheel out of the material that’s considerably lighter than an aluminum one. Competition magnesium wheels made by Halibrand and Campagnolo found their way to the Indianapolis 500 and onto years’ worth of Ferrari endurance and Formula 1 cars. Real magnesium wheels generally aren’t found on the street. But here’s an exception.
If you keep up on American high performance, you’re doubtless aware that Cadillac not only produces some highly credible sports sedans, but also participates in the IMSA Weathertech sports car series with its DPi-V.R prototype. That relationship is going to bear some tangible fruit as Cadillac prepares to roll out its 2022 CT4-V Blackwing and CT5-V Blackwing next summer, representing Cadillac’s new performance pinnacle. They will become the only vehicles in General Motors’ global product lineup to offer actual forged magnesium wheels as optional factory equipment. Magnesium has some ideal properties when cast into wheels: It makes for crisper chassis response by reducing unsprung weight at the car’s corners, and the metal processes vibrations by turning them into heat energy, which is harmlessly dissipated.
Jim Donnelly On Wheels 