The 20-inch forged and cast aluminum wheels will be available in polished, chrome and machine-painted finishes. They were tested at GM's Milford and Mesa proving grounds and with mathematical modeling.
How The Wheels are Made
GM's wheels begin with a one-piece, aluminum ingot that's machined into several designs. A forging process aligns the metal grain so it flows along the contours of the wheel for maximum strength and fatigue resistance. After forging, each wheel is heat-treated for strength and hardness.
More Coming
GM says we can expect to see more 20-inch and larger wheels for GM cars and trucks coming in 2004. You can purchase the wheels from any GM dealership.

