There is a wide range of engine oil additives available on the market. All claim to improve performance, fuel economy and engine life. However, there does not seem to be any that are endorsed by car manufacturers. On this basis, which would be the best additive for a specific car model? Engine oils are manufactured to certain minimum standards set by the automotive industry. The specification includes several additives.
These additives are specially formulated by oil companies to enhance the oil's ability to reduce friction, function as a heat-transfer medium (internal cooling) and inhibit corrosion.
Because of the extreme pressure and heat that oil is exposed to inside the engine, it must also be able to endure the harsh conditions without deteriorating too quickly.
Manufacturers run extensive tests when developing a new engine to ensure it meets the lubrication requirements for various alloys inside the engine.
It is, therefore, not surprising that no manufacturer will recommend after-market additives for engine oil. For that matter, neither will oil companies.
So, the best thing you can do for your car is to invest in a quality oil that meets the vehicle's specifications, which are spelt out in the owner's manual.