high zinc engine oil is a type of motor oil that contains high levels of zinc additives. This type of oil is designed to reduce friction in engines, resulting in reduced engine pressure and increased performance. It's ideal for older cars and hot rods.

Zinc is a critical component of lubricants, which is why it's often used in a wide variety of motor oils. It provides excellent anti-wear protection and may also help retard oxidation, which is the natural wear process that occurs when a lubricant's molecules react with oxygen.

The level of zinc in an oil is generally shown as "Zinc, Mass %" or "Zinc PPM". It can also be expressed as a ratio to the Total Base Number (TBN) and is based on the mass percentage of ZDDP, which is the most common zinc-based additive.

ZDDP, scientifically known as zinc dialkyldithiophosphate, was a popular anti-wear additive for years. However, it has since been restricted by API service classifications due to phosphorus issues.

Fortunately, many lubricant manufacturers are producing oils that don't contain phosphorus and/or zinc. Rather, these motor oils offer advanced synthetic base oils that lubricate metal parts and withstand heat, allowing them to last longer.

These motor oils are also formulated with advanced technology that protects the engine from extreme temperatures. They can stand up to both cold start and high operating temperatures.

The best thing about these high zinc engine oils is that they don't require you to replace the oil during break-in. This is because they have a higher concentration of heavy-duty anti-wear agents, which can provide superior protection against uneven wear and damage during that time.