
Technically the rim is the outer perimeter of the wheel (which is what the tire surrounds.) Today, wheels without hubcaps are referred to as rims. Rims are made from an aluminum alloy, when cars were first produced steel wheels were used. Alloy wheels are lighter and allow for better handling of the vehicle.
Custom car rims are rims that are not available from the manufacturer. Factory rims are an upgrade offered on the sales lot as an upgrade but the selections are limited. Custom car rims come from aftermarket dealers and have many styles and finishes.
For the best looking custom car rims measure the current diameter of the factory wheels and go one to two inches larger. A slightly larger rim gives a fuller, more commanding appearance. Also consider the year the vehicle was made, the rims should coincide with the period the car came from- classic cars demand classic rims.