The Best ZDDP Oil Additive & Cam Assembly Lube

ZDDP Performance from ZDDPlus

ZDDPlus is the original, best researched and documented cam wear solution available.

zdd oil additive information

ZDDPlus™ is an oil supplement that contains very high concentrations of the well-known additive ZDDP (Zinc Dialkyl Dithiophosphate), which has been the primary EP (extreme pressure) ingredient in all quality motor oils for over 70 years. Learn more why ZDDP is critical for your vehicle in our FAQs

ZDDP Perfect for Classic Cars

Tech Briefs & Guides
ZDDPlus™ ZDDP Oil Additive

ZDDPlus™ ZDDP Oil Additive

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ZPaste™ Cam Assembly Lube

ZPaste™ Cam Assembly Lube

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Why ZPlus?

The sliding cam-to-cam-follower interface in a non-roller lifter engine requires a special anti-wear additive, which has historically been ZDDP. After 70+ years of positive protection afforded by ZDDP, emission system changes are forcing a reduction in the amount of ZDDP in motor oils, leaving your classic or performance car at risk of premature cam and lifter wear.

When a single 4 oz bottle of ZDDPlus™ is added to a normal 5-quart oil change, you will restore the proper amount of ZDDP that was found in into pre-1996 oils. Using ZDDPlus™ affords you total control over the characteristics of the oil in the engine by allowing you to use the full 5 quarts of high-grade automotive oil of your choice.


Hear From Our Customers

Ron Hutter Hutter Race Engines

We use ZPlus on all of our Flat Tappet built motors.

Ron Hutter , Hutter Race Engines
“Big Daddy” Don Garlits

ZDDPlus is the best insurance to protect your classic or high-performance flat-tappet engine!

“Big Daddy” Don Garlits, NHRA’s #1 Drag Racer of All Time

What is ZDDP?

ZDDP, zinc dialkyl dithiophosphate, is a compound developed in the 1940s. Petroleum companies added it to their motor oils to enhance lubrication. It was held in high regard as being the most cost effective metal on metal anti-wear additive available. The silicate-based fluid got its start in airplane engines. Designers discovered it also worked well in car and truck engines.

Studies found the anti-wear protection with flat tappets and overhead cam lobes impressive. Further investigation uncovered that the benefits applied to any engine part under considerable pressure. In fact, the ZDDP oil additive substantially reduced noticeable wear in any metal to metal situation.

All tests we’ve reviewed conclude that ZDDP is effective at increasing the longevity of internal engine parts. When properly formulated with base oils, 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.

How ZDDP Works

As temperatures rise and surfaces come closer together, ZDDP decomposes, and the resulting chemistry protects critical metal surfaces. When parts move during operation, any sliding or rolling motion takes place on top of or within the ZDDP anti-wear film, which reduces metal-to-metal contact. This is especially important in modified engines with flat-tappet camshafts because the engine is creating more horsepower than it was designed for, which puts more stress on the engine. High-tension valve springs, often used in racing applications, also increase the potential for cam wear and require additional ZDDP.