Additives are also often referred to as oil additives in the automobile industry. These are compounds that are meant to improve the performance of lubricants. There are various types of additives each which serve a particular purpose. In many oils additives make up to 5% of the weight of oils. It is important to note that API or American Petroleum Institute or SA motor oils do not have additives. So, they are not capable of adequately protecting engines. So, the additives you choose mainly depends on the application i.e. a pickup truck, diesel engine or a 4x4.
The use of additional additives is not easy to answer. Though some companies such as LIQUI-MOLY, MATHY and WYNNS amongst others sell additives separately adding them to synthetic motor oil is something of personal preference. For instance, some additives prevent rust from forming in the engine; others can alter the viscosity of the oil. That said using additives helps to add that extra bit of protection that every engine needs. If anything they are relatively cheap and do not harm the motor, as many have been extensively tested.
Buying the additives you need is very simple. You can browse through our list above and choose what you need, or you can sort by the manufacturer of the additive. However, make sure that you do a bit of research about the additive you’re purchasing, it will help give you a better idea of what to expect and if it's good for your vehicle’s engine.