Alloy wheels
Alloy wheels are automobile wheels that are made of an aluminum alloy instead of steel. Most new cars have alloy wheels, either as standard equipment or as an option. Older buses and large trucks almost never have alloy wheels, but they have recently become an option on newer models. The first alloy wheels were made of magnesium alloys, but these are no longer made because the magnesium alloys were too weak and would eventually crack.