Most of us who are into cars love old cars, from the way they feel when we get behind the wheel to the way they look parked in our driveways. Many of these vehicles need a special type of motor oil with zinc in it to keep them running right and looking great.

Modern oils have very little Zinc (ZDDP) in them due to the fact that it can interfere with some engine sensors and also damage catalytic converters. But, oil testing done on older engines has shown that there is a short period of time during engine start up where a non-zinc oil won't provide sufficient metal-to-metal lubrication to avoid friction between flat tappet cams and their followers.

So, the big question is how do we get the anti-wear protection back into our motor oils? Fortunately, there are several different additives on the market that when mixed into our favorite oil can provide the necessary levels of ZDDP. The most popular one is probably that STP oil treatment you see on AutoZone shelves, but there are also Lucas engine break in oil and Amsoil Z-Rod based oils available.

Zinc (or more specifically, ZDDP) is an excellent sacrificial anti-wear additive that bonds with the surfaces of moving metal parts. The biggest need for it in a classic car or hot rod is in the camshaft, where its lobes push down on the valve stems to open the engine's valves. The parts that press against these lobes are called the followers and they roll or slide along the lobe's surface. When these two parts are squeezed together at high speeds, intense pressure is created that can wear out the lobes and followers and create the need for anti-wear protection.