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At AutoFastFit,  we pride ourselves in only keeping the best brands and brands we trust. Auto Fast fit is a family run business established over 40 year ago.  We have been oil additives since then and take pride in only offering the premium quality car parts and additives at discounted prices. we keep various brand options for each product, which will allow you to choose by price or preferred brand.

Quality is guaranteed at  Only approved products are listed, which will not affect the cars manufacturers waranty.  Browse through our large range of car products.

Oil additives

 Car Engine Image Gallery
Oil additives are chemical compounds that improve the lubricant performance of base oil. The manufacturer of many different oils can utilize the same base stock for each formulation and can choose different additives for each specific application.


Engine oil (also sometimes called motor oil) has two primary purposes: To lubricate the moving parts of your engine which minimizes friction and to protect metallic surfaces from the process known as corrosion -- aka rust. It's rare, however, that engine oil can do these things without the addition of extra chemicals and the most important of these engine oil additives are viscosity index improvers (VIIs).

The viscosity of oil is more or less equivalent to its thickness, its willingness to flow freely through the engine and coat all the parts that need coating. Oil with too high a viscosity will be reluctant to flow and will gum up the works; oil with too low a viscosity will flow through theengine like water, not sticking around long enough to do its job. Furthermore, the viscosity of oil changes with temperature, becoming more viscous when cold and less viscous when hot, so viscosity is affected by both the weather and how warm your engine is.

The tendency of the viscosity of the oil to change with temperature is called its viscosity index and viscosity index improvers are used to adjust this index to make the change in viscosity small enough throughout the car's normal range of temperatures that the oil will be useful whether your car is just being started on a winter morning or driven at engine temperatures of over 200 degrees Fahrenheit (93.3 degrees Celsius). Almost all modern engine oils contain VIIs.

Two other common types of engine oil additive are rust inhibitors and detergents/dispersants. The latter help disperse sludge that can build up in the engine over time. Zinc is also added to many motor oils to protect engine surfaces.