Have you ever struggled when mounting wheels trying to get everything centered and having to rely on your Wheel Lugs to center the wheel and after you hand tighten the lugs it seems that the one that felt tight after you move to the next was loose again? that's because you're relying on the studs and lugs to try to center the wheel on the hub this isn't the case all the time some wheels have center hubs to perfectly fit the hub on your assembly * Check Manufacture specs * with that being said we will go more in depth for the pro's of running Wheel Spacers and Hub Centric Rings.
Hub Centric Rings:
These Hub Centric Rings will effectively Center the wheel around the hub rather than relying on your Lugs and Studs to take all the weight and pressure while installing your wheels, These will help eliminate any high speed vibrations due to the wheel not being correctly centered to the hub you ever felt a slight shake in your cars body and/or steering wheel while driving say a freeway or down a nice long stretch of road that's due to the wheel being ever so slightly off centered from the hub basically causing the rotational mass to change and feel unnatural while driving.
All though Hub centric rings are not required they are a Must have item when you are getting those super clean wheels and why not help yourself for that extra piece of mind knowing you wont have issues later down the road.
Wheel Spacers:
Wheel Spacers there are some people that will nay say against them but truth in the matter is they really do benefit for you with Multiple different things such as improved handling pushing the wheels out just enough to grip harder and handle turns by widening the distance between the left and right wheels especially from OEM factory fitment plus it will give it that proper or wanted look to sit flush with fenders vs. all skinny looking and tucked in like how majority of factory cars come. This will allow wider wheels and tires to really give your ride that look or stance you're going for or even just giving it that wider track feel when putting wider tires on. They are easy to install, Inexpensive and will definitely give your ride that unique look you are trying to go for or looking to go for and on the big plus side is if you already have Big Brakes or plan on running bigger brakes these will help set your wheel far enough for clearance and that's always a plus!
Check out the Video below to see a better understanding of Hub Centric rings and Spacers!