The term "rim" is used interchangeably with "wheel". The rim is the edge of the wheel that the tire is fitted upon. The ring of the wheel is the rim, and the center of the wheel is attached to the rim. The rim and center together make up the wheel. Wheels are circular disks or rings on which automobile tires are mounted. The tires on a vehicle are the only things touching the road surface.

Tire technology is at an all-time high and the quality of rims keeps getting better. Great tires can do wonders even for an average car. Just because a tire fits on a particular rim does not mean it is compatible. Tire sidewall strength, the rim lip and tire bead type (the seal between tire and rim) and load ratings are a few factors that affect compatibility.

Plus sizing, or increasing the size of the rim and tire, is the best way to improve both the performance and appearance of a vehicle. . By using a larger diameter wheel with a lower diameter tire, it's possible to maintain the overall diameter of the tire.

Rims almost always survive the lifetime of a car. One the other hand, tires are subjected to friction occurring from constant contact with the road. This causes the tread on the outer perimeter of the tire to eventually wear away. When the tire tread becomes too shallow, the tire wears out and must be replaced. Front tires, especially on front wheel drive vehicles, have a tendency to wear out more quickly than rear tires. Routine maintenance should be done periodically to even out tire wear. This includes tire rotation (exchanging the front and rear tires with each other).

It is not enough if a car merely has a powerful engine, transmission and suspension. A good rim and tire are paramount to a vehicle's performance. Automobile companies focus a lot of attention to the tire and the rim while designing and manufacturing their models.