Oil Additives

Oil additives can be added to enhance the additive package in the oil or modify the oil properties and keep your engine lubricated. STP® Oil Additives can help reduce friction, heat buildup and overall engine wear. In addition, specialized STP® Oil Additives can help stop oil leaks, reduce oil consumption and exhaust smoking.

Not sure which oil additive to use?  See our Fuel & Oil Additives guide here.

Oil Treatment

Oil Treatment

  • Helps protect against engine wear
  • Contains zinc anti-wear agent ZDDP
  • Reduces oil burning

Help lubricate moving engine parts and reduce oil consumption.

When choosing an oil additive, below is some common terminology and ingredients:


ZDDP (Zinc Dialkyl Dithio Phosphate) is an excellent anti-wear compound, but the amount is limited in the latest motor oil specifications. Additional ZDDP can be provided by oil additives which helps reduce friction, heat and wear. Older vehicles have more metal-to-metal sliding contact than newer vehicles; therefore, additives like ZDDP are very important in older cars.  You can find ZDDP in our STP® Oil Treatment and other STP® Oil Additives.


STP® Ceramic Oil Treatment uses Ceramic Si02 technology to provide an advanced layer of protection by increasing lubrication between metal to metal parts and prevents engine deposit formation. This durable ceramic coating remains even after oil is changed with extended protection up to 15k miles


Viscosity Index Improvers change the viscosity of oil, particularly at higher temperatures, to provide thicker lubricant layers and reduce wear. Increasing the high-temperature viscosity can also reduce the leakage of oil into the combustion chamber, and therefore reduce oil consumption and smoke generation.


Corrosion inhibitors help protect the engine from water and acids formed from combustion gases in the crankcase.


Detergents keep the fine contaminant particles (soot) suspended in the oil so they can be removed by the filter and not coat the engine parts.


Seal swell ingredients in Stop Leak products rejuvenate seals and gaskets to help stop minor oil leaks.


Smoke Treatments are specifically designed to reduce oil burning and exhaust smoke when motor oil enters the combustion chamber and is burned along with fuel. This condition, known as oil blow-by, often results when friction and metal-to-metal contact have worn parts and created gaps between the cylinder walls, piston rings and valve guide seals.