Magnesium is an excellent metal to add to an alloy to make wheels. Because magnesium is 1.5 times less dense than aluminum, while retaining similar specific strength and damping capacities, it is possible to make a mag wheel lighter than an aluminum alloy wheel of the same strength. Particularly in the 1960s, magnesium racing wheels were en vogue. Though developed for motorsport applications, the mag wheel was soon adopted to street use by the enthusiast community. Given that this simple wheel design was quite popular and featured five slotted holes, they became known as ‘slot mags’.
This design of wheel has been available for decades in a wide variety of sizes from a wide variety of manufacturers. From American Racing and Cragar to Ansen and Gyro, every wheel manufacturer seemingly had a wheel that looked like this. And that’s to say nothing of the countless small international shops building them in Italy and Japan. If you have a particular application that you’d like to find a set of slots for, you likely won’t be waiting long.
I can’t imagine why, but it seems that people selling slot mags on the internet are not exactly adept at taking good quality photographs of the items they have for sale. This phenomenon probably has nothing to do with demographics. In any case, this particular set was built by Ansen, and features 15X7 dimensions with a huge 5X5" bolt pattern, most likely for a large old GM. Perhaps a 1970 Buick Riviera? If you think you absolutely need to own them, find them here on eBay.
The fact of the matter is, the simplicity of the design works in favor of the slot mag. This design works well in almost every vintage application. They’ve been used successfully on gassers, hot rods, muscle cars, dune buggies, vans, Volkswagens, sports cars, off-road trucks, and road racers for decades. If the car doesn’t look good with a nondescript wheel like this, it’s not an inherently well designed car. A truly great car design has to stand on its own merit without being propped up by a complementary wheel design.
Hell, if slot mags were good enough for Starsky & Hutch, they’re good enough for me.