A lightweight, rigid wheel cast or forged from a magnesium alloy, originally developed for racing to reduce unsprung weight and improve heat dissipation. In casual shop talk, the term broadly applies to any custom alloy wheel, even those made entirely of aluminum. True magnesium wheels remain highly specialized due to their cost, corrosion susceptibility, and flammability risks.
Heard on the job
I found a set of vintage slot mag wheels for the Mustang, but they need a serious polish.
Insider tip
True magnesium wheels are incredibly light but prone to cracking and rapid corrosion if the protective finish is compromised.
Also heard as
- mag
- mags
Do not mix it up with
- Alloy wheel: Alloy wheels are typically made of aluminum, whereas true mag wheels contain magnesium, though the terms are often used interchangeably.