The term “Control Arm” refers to a very common component in modern suspension. Usually seen in Macpherson and double wishbone style suspension, they (along with the other various suspension arms) help hold the wheel in situ at all times.
A wishbone is a type of lower control arm. Its called this due to its “Y” shaped silhouette. Similar to the shape of a wishbone. It differs to a conventional lower control arm in the sense it is found being used in conjunction with another “wishbone” to control the wheels location.
A control arm is simply a Lateral Support that usually attached from the Chassis to the Hub at either its top or its base. Balljoints are used at its ends to allow movement of the hub for both steering imput and vertical suspension movement.
There are various aftermarket control arms available for popular models of car. These range from Direct Factory replacements to ones made from lighter alloys and designed to add additional toe or to allow for adjustment.
Used in conjunction with Polyurethane Bushes these can absolutely transform the way your car handles and are one of the best Bang for Buck modifications you can perform. Installation can usually be performed in a short amount of time, and while there are some things you need to know before attempting this it can be done by your average DIYer in most cases.