When you take your car in for an oil change, you might be wondering what type of motor oil you need. One consideration is additives—both regular and synthetic blend oils contain them since manufacturers wish to enhance engine performance and keep vehicle parts from degrading quickly. Here are a few you’ll often find in your engine oil.

A Guide on Motor Oil Additives

1. Viscosity Index Improvers

Keep in mind that engine oil becomes thicker and more viscous when it’s cold. If the oil is too thick, it won’t flow freely or be as effective in lubricating parts. On the other hand, thin oil won’t protect the engine and coat the components as well. This unstable property of the oil makes it difficult to use during temperature fluctuations.

This is why most engine oils have viscosity index improvers, allowing them to adjust their thickness amidst a wide range of temperature changes. These polymer additives help maintain the oil’s viscosity whatever the weather and engine temperature are.

2. Rust Inhibitors

oil changeSince most of the internal components of an engine can rust and corrode, they need protection against constant exposure to moisture, corrosive acids, and other contaminants.

Manufacturers add rust inhibitors in the blend as a defense against these hazards. These additives create a protective barrier around the parts, preventing the chemical reaction of moisture on the metal. Some corrosion inhibitors protect specific metals, so check what your choice contains when you go for an oil change. 

3. Detergents & Dispersants

Two more commonly used additives in motor oils are detergents and dispersants. Both work to prevent—or at least delay—the formation of contaminants like sludge and deposits that can damage the engine over time. 

Dispersants absorb and contain solid debris to disperse sludge, which can build up over time. On the other hand, detergents work on frequently overheating metal surfaces by keeping them free of deposits and neutralizing acids in the oil. These additives have magnesium and calcium to maintain their alkalinity or basic nature and offset acidity. 


Learn more about additives when you go for an oil change at Landrum Lube. They’re the experts when it comes to conventional and synthetic blend oils. As the premier express lube shop in Spartanburg County, SC, they’ve been offering essential car maintenance services like air filter changes and tire pressure checks for almost two decades. Call (864) 457-3956 today or view their full list of services online.