Steel vs. Zinc. No Contest.
Zinc is no match for steel when it comes to replacing lead wheel weights. Its low density makes it the heaviest and therefore the most difficult to balance among all the cost-effective alternatives. And as a known secondary water contaminant, zinc poses a significant threat to the environment.
Steel weights, on the other hand, are much closer in size to their lead counterparts, which helps them deliver a higher number of one-spin balances. And they carry none of the environmental risks associated with zinc