As much as 25% from the liquid inside a standard quart of oil is additive. Additives are what really make the oil and establish its performance properties. Additives extend the viscosity variety of the oil, make it possible for it to withstand high pressures and loads, deal with contaminants while in the crankcase, and minimize friction for improved fuel economy.

One in the most critical additives is “Viscosity Index (VI) Improvers”. These support the oil preserve a reliable viscosity as temperature and load alter. “Pour stage depressants” can also be applied to avoid the oil from thickening at reduced temperature for much easier beginning.

Modern-day motor oils also contain detergents and dispersants to cut back varnish and sludge formation to help keep the engine clean. You’ll find also “anti-oxidants” to minimize oil burning once the oil will get hot. This also assists decrease the formation of varnish and carbon deposits within the engine.

Rust and corrosion inhibitors are extra to counteract the dangerous effects of water, unburned fuel and exhaust gases that blow previous the rings and enter the crankcase. This prevents the formation of acids that may pit bearing surfaces. “Foam inhibitors” are applied to decrease the formation of air bubbles since the oil is churned by moving parts. “Wetting agents” aid the oil stick to hot surfaces so it doesn’t run off and leave the metal unlubricated and unprotected.

Lastly, you will discover “anti-wear” and “extreme-pressure” additives. These involve zinc and phosphorus that offer put on protection when metal touches metal. Some racing oils commonly possess a higher dose of zinc to offer further protection in high revving, high load applications.


Engine oil additives and treatments involve friction reducers/modifiers, products that support cut down oil burning, engine flushes to remove carbon. varnish and sludge deposits in the crankcase, and moly and teflon-based crankcase additives that assist lower wear and extend engine life. These products can’t work miracles, but they can reduce oil consumption in older engines and assistance protect newer engines against premature wear.

Most vehicle manufacturers do NOT recommend using any type of aftermarket oil additive. Quality motor oils should have all the additives that are necessary for normal service and to retain oil lubricity between normal oil change intervals. On the other hand, most vehicle manufacturers do NOT prohibit the use of aftermarket oil additives in newer engines.

Aftermarket oil additives make one of the most sense for older, high mileage engines that are burning or leaking oil, or that may be used for severe service or racing.

In recent years, the level of phosphorus has been reduced in motor oil because phosphorus can contaminant the catalytic converter if the engine is burning oil. Phosphorus is an anti-wear additive, so there is some concern that lower levels of this essential additive may increase put on in older engines that have flat tappet cams instead of roller cams. To assist protect older engines with flat tappet cams against wear, using an aftermarket oil additive that contains phosphorus or other anti-wear additives may support prolong engine life.