When the chips are down, an engine oils primary function is preventing wear. These days, formulators are all-in for reducing friction to improve fuel economy, too, which helps to limit harmful vehicle emissions. But some are upping the ante on environmental protection, searching for ways to draw biobased and biodegradable additives into their hand.
Typically, organo-metallic additives are used to avert friction and wear damage, prevent corrosion, reduce foaming and minimize oxidation. Some, such as zinc dialkyldithiophosphate, have multiple functions-in this case, as an antiwear, antioxidant, corrosion inhibitor and extreme pressure additive.