When it comes to your vintage or classic car, your engine means everything. It’s the heart of your vehicle and the reason it’s so beautiful. It inspires admiring whistles from onlookers and helps turn your favorite hot rod into a show-stopping machine.

ZDDP is a popular engine oil additive. It’s found in many different types of lubricants and it’s a common ingredient in heavy-duty motor oils for extreme conditions.

How does it work?

In a nutshell, ZDDP forms a tribofilm, which protects metal surfaces. This film prevents direct contact between metal parts like cam lobes and flat tappet lifters by protecting them from heat and friction.

But, as we all know, modern engines aren’t built to withstand high temperatures and intense pressures. That’s why, in 1996, the American Petroleum Institute changed the formulation of engine oil, reducing the amount of zinc and phosphorus (known as ZDDP) in the formula.

Luckily, there are products like Rislone Hy-per Lube Zinc ZDDP Supplement, which you can add to modern conventional oils to make them work just as well as the zinc-rich oils that your grandparents used in their cars. But if you own a classic or muscle car that uses flat tappet lifters, it’s even more important to get the proper amounts of ZDDP in your engine’s oil.