Mettle Plus EMT reduces the need for ZDDP

The background on ZDDP & how ZDDP Works 

Zinc dialkyl dithiophosphate is a silicate-based lubricating compound developed in the 1940s that was first used in airplane engines. It wasn't long before petroleum companies added it to their motor oils to inhibit wear in automotive engines. It was considered the most effective metal-on-metal anti-wear additive available.


As a car's engine heats up and engine parts begin to make contact, so too does ZDDP heat up. As it becomes volatile, it breaks down into a wear-protecting phosphate compound that coats and protects the engine's metal surfaces, thus reducing the kind of metal-to-metal contact that can make an engine seize up. This is especially important in high horsepower engines, like those found in classic and racing cars.


As an additive, ZDDP is also known to have antioxidant and corrosion resistant properties. These are useful qualities for classic car enthusiasts since their engines can sit for extended periods.

Toxicity Concerns


Over the last 40 years, there has been considerable pressure to reduce the use of ZDDP in motor oil applications because of long-term toxicity concerns. The chemical compound is especially toxic to aquatic wildlife and has long-lasting effects when it finds its way into the water table. While proper safety and disposal practices could mitigate this problem, pollution is not the only issue associated with this oil additive.

Bad for Catalytic Converters


The same phosphate compound that protects a car's engine is on the other hand detrimental to its catalytic converter, which in modern cars is the part responsible for reducing carbon emissions. Over the past several decades, the EPA has reduced acceptable levels of carbon emissions while increasing the amount of miles guaranteed by a catalytic converter from 50,000 to 120,000 or ten years. As a result, the automotive industry has developed motor oils with ever-decreasing concentrations of ZDDP. This has now turned into a movement to completely eliminate the chemical compound.

Removing ZDDP from Engine Oils

So as an alternative to ZDDP use Mettle Plus EMT instead and protect your engine and gearbox.