What is Zinc and how does it compare to detergents?

All About Zinc

Recently there has been quite a lot of talk about ZINC, so we’re going to explain why that is as well as the difference it makes during break-in. What is Zinc ? We will cover that too.

The word is out regarding the reduction of Zinc in today’s motor oils, but there is a lot more to the story. Specifically, not all Zinc additives and high Zinc content oils perform the same. Here are four facts related to Zinc. First, the oil additive generally referred to as Zinc is technically Zinc Dialkyl Dithiophosphate (ZDDP). As stated in the book Lubrication Fundamentals,” In heavily loaded applications, flat tappet cam followers operate on partial oil films at least part of the time. Lubricants with anti-wear additives are necessary if rapid wear and surface distress are to be avoided. oil additive Zinc Dithiophosphate is to provide anti-wear activity for the camshaft and lifters.”

Second, Zinc (ZDDP) is not a lubricant until heat and load are applied. Zinc must react with heat and load to create the sacrificial film that allows Zinc to protect flat-tappet camshafts and other highly loaded engine parts.

Society of Automotive Engineers’ Automotive Lubricants Reference Book states, “ZDDP is the predominant anti-wear additive used in crankcase oils, although it is a class of additive rather than one particular chemical. Sensitivity of the additive to commence giving anti-wear protection varies inversely with the thermal stability of the additive.”

As a result, the third fact is that not all Zinc (ZDDP) additives react under the same level of heat and load. Zinc has different “Burn” rates. Some Zinc additives have slower “burn” rates that require more heat and more load to activate than other Zinc additives. For example, Passenger Car Motor Oils (PCMO’s) typically feature a faster burning Zinc than Diesel Engine Oils due to the lower compression ratios found in gasoline engines compared to compression ignition diesel engines. As a result, not all “High Zinc” oils have the same activation rate. Joe Gibbs Driven BR Break-In oil uses a “Fast Burn” ZDDP that activates quickly. Fourth, detergent additives “compete” against Zinc in the engine. Detergents are additives that clean the engine, but detergents don’t distinguish between sludge, varnish and Zinc – it cleans all three away. The “old school” theory on engine break-in was to run non-detergent oils, and this allowed for greater activation of the Zinc additive in the oil. Joe Gibbs Driven BR Break-In oil features a low detergent formula to allow the “Fast Burn” Zinc additive package to activate faster and to full extent.

Characteristics of Zinc and Detergents determine how quickly and to what extent an oil will provide sacrificial boundary film protection for your engine.

In order to achieve seamless protection for your flat-tappet camshaft or highly loaded engine, you need to establish the presence of the correct “Burn Rate” additives on the surface of the camshaft, lifters and other highly stressed engine parts. A properly matched set of assembly lubricants and break-in oil is of high importance.

Joe Gibbs Driven Engine Assembly Grease places “Fast Burn” anti-wear additives on the critical wear surfaces of your engine, and the Joe Gibbs Driven BR Break-In Oil provides the correct balance of “Fast Burn” Zinc additives and low levels of detergents to quickly establish a sacrificial anti-wear film throughout your engine. Rapidly establishing this anti-wear film in your engine provides a lower wear break-in and extends engine parts life.

For example, using the system of Engine Assembly Grease followed by the BR Break-In oil and then using XP1 Synthetic Racing Oil, allowed Joe Gibbs Racing to double flat-tappet lifter life from 600 miles to 1200 miles!

Joe Gibbs Driven Assembly Grease followed by Break-In Oil and then Synthetic Racing Oil or Hot Rod Oil like the primer, sealer and base color of automotive paint. It really does make a difference when you apply the right products for the job in the correct order!

Regardless of the lubricants you use, it is of vital importance that you properly prime the oiling system before starting a new or re-built engine. Please follow your camshaft manufacturers’ break-in procedure for flat-tappet camshafts.

What is Zinc? Zinc, or spelter, is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element of group 12 of the periodic table.



Zinc vs Detergent is a growing hot topic in the all engine applications. Detergent and dispersant additives “compete” against zinc in the engine because they are polar molecules as well. Detergents and dispersants clean the engine, but they don’t distinguish between sludge, varnish and zinc – they clean all three away.

Modern API certified oils contain higher levels of detergents and dispersants due to the exhaust gas recirculation (EGR) systems on passenger cars and diesel trucks. The “old school” theory on engine break-in was to run non-detergent oils, and this allowed for greater activation of the zinc additive in the oil.

Joe Gibbs Driven BR Break-In oils utilize the correct balance of anti-wear additives and detergents, so you don’t need to buy expensive additives to try to “fix” a low zinc (ZDDP) oil.

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