http://www.popularmechanics.com/cars/how-to/a1171/4208682/
I've seen plenty of corroded steel rims leaking air past a rust-curdled bead seat surface. Guess what? Alloy wheels can corrode and leak air just like steel ones do. Today, alloy rims are no longer limited to the rich and famous -- even small, inexpensive cars are coming with alloys as standard. It's no surprise that those cheaper cars tend to get less maintenance than the more expensive ones -- and that includes keeping the wheels clean. Unfortunately, when alloys go bad, they aren't always as easy to fix as steel wheels. A steel wheel can be wire brushed and repainted good as new. However, this alloy rim is basically a doorstop now. The rim is so pitted with corrosion it's no longer safe to use.
I've seen plenty of corroded steel rims leaking air past a rust-curdled bead seat surface. Guess what? Alloy wheels can corrode and leak air just like steel ones do. Today, alloy rims are no longer limited to the rich and famous -- even small, inexpensive cars are coming with alloys as standard. It's no surprise that those cheaper cars tend to get less maintenance than the more expensive ones -- and that includes keeping the wheels clean. Unfortunately, when alloys go bad, they aren't always as easy to fix as steel wheels. A steel wheel can be wire brushed and repainted good as new. However, this alloy rim is basically a doorstop now. The rim is so pitted with corrosion it's no longer safe to use.
