Zinc is a polar molecule that attracts iron surfaces and forms a sacrificial film on metallic surfaces. The film provides anti-wear protection when the metal is under load or heat.

Zinc can also act as a corrosion inhibitor and oxidation inhibitor to combat heat buildup and protect the engine oil against rust. However, the zinc additive used in most premium lubricants has been progressively reduced over time.

There are many options on the market to add more zinc to your engine oil, but be sure you know what you're getting into and don't add too much.

Use a zinc-based lubricant with a phosphate-free base oil and be aware of any added additives that may contain phosphorus. This is because phosphorus can cause carbon buildup in the engine and may shorten the life of catalytic converters, which are vital to reducing emissions in newer vehicles.

A zinc-based lubricant can be mixed properly with a base oil at a particular temperature, but if the base oil is too hot, the zinc additive won't mix with the oil. That's why it is always important to use a high-quality, well-mixed, high-zinc motor oil that has been properly mixed with an additive designed for your older engine.

In addition to preventing premature wear and promoting longevity, a high-zinc motor oil can reduce horsepower loss. It can help maintain horsepower during break-in and even after break-in, when the cam shaft is subjected to a constant barrage of heat and pressure.