Alloy rims, also known as aluminum rims, are a type of wheel made from aluminum or magnesium alloys. They are often used as a performance upgrade for cars and trucks, as they are lighter and stronger than traditional steel wheels. Alloy rims are also popular for their aesthetic appeal, as they come in a variety of styles and finishes that can enhance the appearance of a vehicle. However, they can be more expensive than steel wheels and may require special care to maintain their finish and integrity.