What are wheel spacers?
Wheel spacers allow you to give your car a wider more aggressive setup without having to buy wide wheels. Spacers come in various sizes, generally ranging from 3mm to 30 mm. Spacers can also help if you are having clearance issue with your wheels as well.
What are wheel adapters?
Wheel adapters allow you to run wheels that have a different bolt pattern than the one your car has. Often with VW and Audi’s, adapters are used to run Porsche wheels or Corvette Sawblades. Adapters are spacers as well as they come in various widths as well as change the bolt pattern of your car. Adapters bolt onto your cars existing hub and then has new holes for the new bolt pattern.
What are hub centric rings?
Hub rings are used when the center bore of your wheel is larger than the hub size that is on your car. This will fill that space between the cars hub and the wheel.
The purpose of the centric ring is to fit the wheel perfectly to the wheel hub, preventing vibration and shaking to the steering wheel during driving, which typically appears around speeds of 40-60 mph.
Rings come in durable industrial plastic, as well as aluminum.
Hub centric vs. lug centric spacers
Hub centric is when the center bore of the spacer is sized to fit perfectly onto the hub of the car. This hub-centric connection, allows the spacer to be centered by it’s connection to the axle hub.
When putting on a wheel, the bolts hold the wheel firmly to the mounting plate, but it is the spacer-to-axle hub connection that actually holds the weight of the car.
Lug centric is when the hub of the spacer is bigger than the hub on the car, causing there to be a gap or space between them, rather than firm contact. This means when putting on the wheel, the wheel and spacer are centered on the car by the bolts.
This is not a recommended way to drive as any impact will be taken by the lug nuts which could result in them sheering off.
This issue could be solved by getting hub centric rings to fill the space between the spacer and hub itself.